Cesanta
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TLS hostname verification bypass in Cesanta Mongoose's built-in TLS stack (versions prior to 7.22) lets an on-path attacker holding a wildcard certificate for a parent domain impersonate arbitrarily deep subdomains, defeating certificate validation for clients that use the embedded TLS backend. The flaw stems from mg_match() wildcards crossing DNS label boundaries, so *.example.com wrongly matches foo.bar.example.com. A vendor patch exists in 7.22, but no public exploit identified at time of analysis.
HTTP request smuggling in Cesanta Mongoose embedded web server/network library before 7.22 lets a remote unauthenticated attacker desynchronize an HTTP/1.0 reverse-proxy front-end from the Mongoose back-end. A buggy length check in http_cb() (src/http.c) never sets is_http_1_0, so Mongoose honors Transfer-Encoding: chunked framing that an HTTP/1.0 proxy ignores, allowing the attacker to smuggle requests past the proxy and reach unauthorized functionality or alter application state. Rated CVSS 9.1; a vendor patch exists (7.22), but no public exploit and no EPSS/KEV data were provided at time of analysis.
HTTP request smuggling (CL.TE desynchronization) in Cesanta Mongoose embedded web server before 7.22 lets a remote unauthenticated attacker craft a request bearing both Content-Length and Transfer-Encoding: chunked headers. Because mg_http_parse()/http_cb() accept both and prioritize chunked encoding while a front-end reverse proxy that prefers Content-Length draws a different request boundary, an attacker can smuggle a second request that reads or modifies resources belonging to another user's context. No public exploit is identified at time of analysis; the issue is fixed in 7.22 which rejects requests containing both headers.
Denial of service in Cesanta Mongoose before 7.22 lets a remote, unauthenticated attacker crash any TLS service (HTTPS, MQTTS, or WSS) built on the MG_TLS_BUILTIN stack by sending a single crafted TLS ClientHello whose session_id_len byte is used as an unvalidated buffer index, triggering an out-of-bounds read. The flaw sits in the built-in TLS server handshake function mg_tls_server_recv_hello() and requires no authentication or user interaction. There is no public exploit identified at time of analysis and it is not listed in CISA KEV, but the trigger is trivial and the issue was disclosed by VulnCheck.
Path traversal in Cesanta Mongoose's SSI processing allows an authenticated network attacker to read arbitrary files accessible to the Mongoose process by embedding directory traversal sequences in #include file or #include virtual SSI directives. The mg_ssi() function in src/ssi.c constructs filesystem paths from directive arguments without invoking the existing mg_path_is_sane() validation, bypassing the only guard against traversal. Exploitation is constrained to deployments compiled with MG_ENABLE_SSI and a configured ssi_pattern; no public exploit has been identified at time of analysis.
Reflected cross-site scripting in Cesanta Mongoose (all versions prior to 7.22) allows a remote unauthenticated attacker to inject arbitrary JavaScript into a victim's browser by crafting a percent-encoded URL path targeting the directory listing handler. The `mg_http_serve_dir()` and `listdir()` functions in `src/http.c` insert the decoded request URI directly into `<title>` and `<h1>` HTML elements without HTML entity escaping, and the resulting script executes in the Mongoose origin. Exploitation requires both that the server was compiled with `MG_ENABLE_DIRLIST` enabled and that a victim user is persuaded to visit the malicious link; no public exploit or CISA KEV listing is identified at time of analysis.
Stored cross-site scripting in Cesanta Mongoose's directory listing feature allows an attacker with filesystem write access to a served directory to plant a file whose name contains HTML or JavaScript markup; when any user browses that directory, the raw filename is reflected into the HTML page without escaping, executing arbitrary script in the Mongoose origin. All Mongoose versions prior to 7.22 with MG_ENABLE_DIRLIST enabled are affected. No public exploit or CISA KEV listing is confirmed at time of analysis; the vendor-released fix is available in Mongoose 7.22.
Multipart body parsing in Cesanta Mongoose before 7.22 can be manipulated by a remote unauthenticated attacker to truncate headers, filenames, or boundary values through injection of a lone carriage return or line feed. The logic error in mg_http_next_multipart() causes CRLF-scanning loops to terminate prematurely on any single CR or LF character rather than requiring the full two-byte CRLF sequence, enabling content-type spoofing that can cause downstream application logic to accept dangerous or disallowed content. No CISA KEV listing or public proof-of-concept has been identified at time of analysis; the fix is confirmed in release 7.22.
Improper verification of cryptographic signatures in Cesanta Mongoose versions up to 7.20 allows remote attackers to bypass GCM authentication tag validation in the mg_aes_gcm_decrypt function. The vulnerability has high attack complexity and requires no user interaction, but provides only integrity impact (not confidentiality or availability). Publicly available exploit code exists, and vendor has released patched version 7.21.
Remote denial of service in Cesanta Mongoose up to version 7.20 allows unauthenticated attackers to trigger an infinite loop via manipulation of TCP option length parameters in the handle_opt function, causing service unavailability. Publicly available exploit code exists. Patch released in version 7.21.
Authorization bypass in Cesanta Mongoose up to version 7.20 allows remote, unauthenticated attackers to bypass TLS certificate signature verification in the P-384 public key handler (mg_tls_verify_cert_signature function in mongoose.c), potentially enabling man-in-the-middle attacks or unauthorized access. The attack is highly complex (CVSS AC:H) but publicly disclosed exploit code exists, with vendor-released patch available in version 7.21.
Stack-based buffer overflow in Cesanta Mongoose mDNS Record Handler (versions up to 7.20) allows remote attackers to trigger memory corruption via malformed mDNS record data in the handle_mdns_record function. The vulnerability requires high attack complexity and network-level access but results in limited confidentiality, integrity, and availability impact. Publicly available exploit code exists; vendor released patched version 7.21 with immediate availability.
Heap-based buffer overflow in Cesanta Mongoose versions up to 7.20 allows unauthenticated remote attackers to compromise confidentiality, integrity, and availability through malicious TLS 1.3 handshake manipulation. The vulnerability resides in mg_tls_recv_cert() function's improper handling of the pubkey argument during certificate processing. Publicly available exploit code exists (CVSS temporal E:P), and vendor-released patch is available in version 7.21. CVSS base score 7.3 reflects network-accessible, low-complexity attack requiring no privileges or user interaction.
A vulnerability was detected in Cesanta Mongoose up to 7.20. This impacts the function mg_chacha20_poly1305_decrypt of the file /src/tls_chacha20.c of the component Poly1305 Authentication Tag Handler. The manipulation results in improper verification of cryptographic signature. The attack may be launched remotely. This attack is characterized by high complexity. The exploitability is said to be difficult. The exploit is now public and may be used. The vendor was contacted early about this di...
A security vulnerability has been detected in Cesanta Mongoose up to 7.20. This affects the function getpeer of the file /src/net_builtin.c of the component TCP Sequence Number Handler. [CVSS 3.7 LOW]
A weakness has been identified in Cesanta Mongoose up to 7.20. The impacted element is the function mg_sendnsreq of the file /src/dns.c of the component DNS Transaction ID Handler. [CVSS 3.7 LOW]
Null pointer dereference in add_ca_certs() in Cesanta Mongoose before 7.2 allows remote attackers to cause a denial of service via TLS initialization where SSL_CTX_get_cert_store() returns NULL. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
An integer overflow vulnerability exists in the WebSocket component of Mongoose 7.5 thru 7.17. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Improper Neutralization of Delimiters vulnerability in Cesanta Mongoose Web Server v7.14 allows to trigger an infinite loop bug if the input string contains unexpected characters. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and force the application to read unintended heap memory. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and force the application to read unintended heap memory. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and force the application to read unintended heap memory. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and force the application to read unintended heap memory. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and force the application to read unintended heap memory. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and produce a segmentation fault on the application. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Improper Neutralization of Delimiters vulnerability in Cesanta Mongoose Web Server v7.14 allows to trigger an out-of-bound memory write if the PEM certificate contains unexpected characters. Rated high severity (CVSS 7.0), this vulnerability is no authentication required. No vendor patch available.
Integer Overflow or Wraparound vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and produce a segmentation fault on the application. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows to write a NULL byte value beyond the memory space dedicated for the hostname field. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_do_gc function in the mjs.c file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_mk_ffi_sig function in the mjs.c file. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_array_length function in the mjs.c file. Rated medium severity (CVSS 5.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_destroy function in the msj.c file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An Out of Bounds Write in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_op_json_stringify function in the msj.c file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_op_json_parse function in the msj.c file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs+0x4ec508 component. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_getretvalpos function in the msj.c file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cesanta MJS 2.20.0 has a getprop_builtin_foreign out-of-bounds read if a Built-in API name occurs in a substring of an input string. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Cesanta mjs v2.20.0 was discovered to contain a function pointer hijacking vulnerability via the function mjs_get_ptr(). Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Due to a failure in validating the length of a provided MQTT_CMD_PUBLISH parsed message with a variable length header, Cesanta Mongoose, an embeddable web server, version 7.10 is susceptible to a. Rated high severity (CVSS 8.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
The HTTP server in Mongoose before 7.10 accepts requests containing negative Content-Length headers. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
An issue found in Cesanta MJS v.1.26 allows a local attacker to cause a denial of service via the mjs_execute function in mjs.c. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Buffer Overflow vulnerability found in Cesanta MJS v.1.26 allows a local attacker to cause a denial of service via the mjs_mk_string function in mjs.c. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Cesanta MJS v2.20.0 was discovered to contain a SEGV vulnerability via mjs_ffi_cb_free at src/mjs_ffi.c. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cesanta MJS v2.20.0 was discovered to contain a SEGV vulnerability via ffi_cb_impl_wpwwwww at src/mjs_ffi.c. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cesanta MJS v2.20.0 was discovered to contain a SEGV vulnerability via gc_sweep at src/mjs_gc.c. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
This affects the package cesanta/mongoose before 7.6. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
In mjs_json.c in Cesanta MongooseOS mJS 1.26, a maliciously formed JSON string can trigger an off-by-one heap-based buffer overflow in mjs_json_parse, which can potentially lead to redirection of. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 (compiled with OpenSSL support) is vulnerable to remote OOB write attack via connection request after exhausting memory pool. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 and 6.7-6.18 (compiled with mbedTLS support) is vulnerable to remote OOB write attack via connection request after exhausting memory pool. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
The mg_http_serve_file function in Cesanta Mongoose HTTP server 7.0 is vulnerable to remote OOB write attack via connection request after exhausting memory pool. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A buffer overflow vulnerability exists in the mg_get_http_header function in Cesanta Mongoose 6.18 due to a lack of bounds checking. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Buffer Copy without Size Check vulnerability could allow attackers to overflow a buffer to corrupt adjacent memory.
An integer overflow in parse_mqtt in mongoose.c in Cesanta Mongoose 6.16 allows an attacker to achieve remote DoS (infinite loop), or possibly cause an out-of-bounds write, by sending a crafted MQTT. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
mq_parse_http in mongoose.c in Mongoose 6.15 has a heap-based buffer over-read. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in Mongoose before 6.15. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Out-of-bounds Write vulnerability could allow attackers to write data beyond allocated buffer boundaries leading to code execution or crashes.
In Cesanta Mongoose 6.13, a SIGSEGV exists in the mongoose.c mg_mqtt_add_session() function. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An exploitable arbitrary memory read vulnerability exists in the MQTT packet-parsing functionality of Cesanta Mongoose 6.13. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An exploitable arbitrary memory read vulnerability exists in the MQTT packet-parsing functionality of Cesanta Mongoose 6.13. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
The mg_handle_cgi function in mongoose.c in Mongoose 6.11 allows remote attackers to cause a denial of service (heap-based buffer over-read and application crash, or NULL pointer dereference) via an. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An exploitable memory corruption vulnerability exists in the Websocket protocol implementation of Cesanta Mongoose 6.8. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An exploitable memory corruption vulnerability exists in the Websocket protocol implementation of Cesanta Mongoose 6.8. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An infinite loop programming error exists in the DNS server functionality of Cesanta Mongoose 6.8 library. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An exploitable arbitrary memory read vulnerability exists in the MQTT packet parsing functionality of Cesanta Mongoose 6.8. Rated high severity (CVSS 8.2), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An exploitable stack buffer overflow vulnerability exists in the MQTT packet parsing functionality of Cesanta Mongoose 6.8. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An exploitable NULL pointer dereference vulnerability exists in the MQTT packet parsing functionality of Cesanta Mongoose 6.8. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An exploitable arbitrary memory read vulnerability exists in the MQTT packet parsing functionality of Cesanta Mongoose 6.8. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An exploitable use-after-free vulnerability exists in the HTTP server implementation of Cesanta Mongoose 6.8. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cross-site request forgery (CSRF) vulnerability in Mongoose Web Server before 6.9 allows remote attackers to hijack the authentication of users for requests that modify Mongoose.conf via a request to. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Use-after-free vulnerability in the mg_http_multipart_wait_for_boundary function in mongoose.c in Cesanta Mongoose Embedded Web Server Library 6.7 and earlier and Mongoose OS 1.2 and earlier allows. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and EPSS exploitation probability 33.2%.
TLS hostname verification bypass in Cesanta Mongoose's built-in TLS stack (versions prior to 7.22) lets an on-path attacker holding a wildcard certificate for a parent domain impersonate arbitrarily deep subdomains, defeating certificate validation for clients that use the embedded TLS backend. The flaw stems from mg_match() wildcards crossing DNS label boundaries, so *.example.com wrongly matches foo.bar.example.com. A vendor patch exists in 7.22, but no public exploit identified at time of analysis.
HTTP request smuggling in Cesanta Mongoose embedded web server/network library before 7.22 lets a remote unauthenticated attacker desynchronize an HTTP/1.0 reverse-proxy front-end from the Mongoose back-end. A buggy length check in http_cb() (src/http.c) never sets is_http_1_0, so Mongoose honors Transfer-Encoding: chunked framing that an HTTP/1.0 proxy ignores, allowing the attacker to smuggle requests past the proxy and reach unauthorized functionality or alter application state. Rated CVSS 9.1; a vendor patch exists (7.22), but no public exploit and no EPSS/KEV data were provided at time of analysis.
HTTP request smuggling (CL.TE desynchronization) in Cesanta Mongoose embedded web server before 7.22 lets a remote unauthenticated attacker craft a request bearing both Content-Length and Transfer-Encoding: chunked headers. Because mg_http_parse()/http_cb() accept both and prioritize chunked encoding while a front-end reverse proxy that prefers Content-Length draws a different request boundary, an attacker can smuggle a second request that reads or modifies resources belonging to another user's context. No public exploit is identified at time of analysis; the issue is fixed in 7.22 which rejects requests containing both headers.
Denial of service in Cesanta Mongoose before 7.22 lets a remote, unauthenticated attacker crash any TLS service (HTTPS, MQTTS, or WSS) built on the MG_TLS_BUILTIN stack by sending a single crafted TLS ClientHello whose session_id_len byte is used as an unvalidated buffer index, triggering an out-of-bounds read. The flaw sits in the built-in TLS server handshake function mg_tls_server_recv_hello() and requires no authentication or user interaction. There is no public exploit identified at time of analysis and it is not listed in CISA KEV, but the trigger is trivial and the issue was disclosed by VulnCheck.
Path traversal in Cesanta Mongoose's SSI processing allows an authenticated network attacker to read arbitrary files accessible to the Mongoose process by embedding directory traversal sequences in #include file or #include virtual SSI directives. The mg_ssi() function in src/ssi.c constructs filesystem paths from directive arguments without invoking the existing mg_path_is_sane() validation, bypassing the only guard against traversal. Exploitation is constrained to deployments compiled with MG_ENABLE_SSI and a configured ssi_pattern; no public exploit has been identified at time of analysis.
Reflected cross-site scripting in Cesanta Mongoose (all versions prior to 7.22) allows a remote unauthenticated attacker to inject arbitrary JavaScript into a victim's browser by crafting a percent-encoded URL path targeting the directory listing handler. The `mg_http_serve_dir()` and `listdir()` functions in `src/http.c` insert the decoded request URI directly into `<title>` and `<h1>` HTML elements without HTML entity escaping, and the resulting script executes in the Mongoose origin. Exploitation requires both that the server was compiled with `MG_ENABLE_DIRLIST` enabled and that a victim user is persuaded to visit the malicious link; no public exploit or CISA KEV listing is identified at time of analysis.
Stored cross-site scripting in Cesanta Mongoose's directory listing feature allows an attacker with filesystem write access to a served directory to plant a file whose name contains HTML or JavaScript markup; when any user browses that directory, the raw filename is reflected into the HTML page without escaping, executing arbitrary script in the Mongoose origin. All Mongoose versions prior to 7.22 with MG_ENABLE_DIRLIST enabled are affected. No public exploit or CISA KEV listing is confirmed at time of analysis; the vendor-released fix is available in Mongoose 7.22.
Multipart body parsing in Cesanta Mongoose before 7.22 can be manipulated by a remote unauthenticated attacker to truncate headers, filenames, or boundary values through injection of a lone carriage return or line feed. The logic error in mg_http_next_multipart() causes CRLF-scanning loops to terminate prematurely on any single CR or LF character rather than requiring the full two-byte CRLF sequence, enabling content-type spoofing that can cause downstream application logic to accept dangerous or disallowed content. No CISA KEV listing or public proof-of-concept has been identified at time of analysis; the fix is confirmed in release 7.22.
Improper verification of cryptographic signatures in Cesanta Mongoose versions up to 7.20 allows remote attackers to bypass GCM authentication tag validation in the mg_aes_gcm_decrypt function. The vulnerability has high attack complexity and requires no user interaction, but provides only integrity impact (not confidentiality or availability). Publicly available exploit code exists, and vendor has released patched version 7.21.
Remote denial of service in Cesanta Mongoose up to version 7.20 allows unauthenticated attackers to trigger an infinite loop via manipulation of TCP option length parameters in the handle_opt function, causing service unavailability. Publicly available exploit code exists. Patch released in version 7.21.
Authorization bypass in Cesanta Mongoose up to version 7.20 allows remote, unauthenticated attackers to bypass TLS certificate signature verification in the P-384 public key handler (mg_tls_verify_cert_signature function in mongoose.c), potentially enabling man-in-the-middle attacks or unauthorized access. The attack is highly complex (CVSS AC:H) but publicly disclosed exploit code exists, with vendor-released patch available in version 7.21.
Stack-based buffer overflow in Cesanta Mongoose mDNS Record Handler (versions up to 7.20) allows remote attackers to trigger memory corruption via malformed mDNS record data in the handle_mdns_record function. The vulnerability requires high attack complexity and network-level access but results in limited confidentiality, integrity, and availability impact. Publicly available exploit code exists; vendor released patched version 7.21 with immediate availability.
Heap-based buffer overflow in Cesanta Mongoose versions up to 7.20 allows unauthenticated remote attackers to compromise confidentiality, integrity, and availability through malicious TLS 1.3 handshake manipulation. The vulnerability resides in mg_tls_recv_cert() function's improper handling of the pubkey argument during certificate processing. Publicly available exploit code exists (CVSS temporal E:P), and vendor-released patch is available in version 7.21. CVSS base score 7.3 reflects network-accessible, low-complexity attack requiring no privileges or user interaction.
A vulnerability was detected in Cesanta Mongoose up to 7.20. This impacts the function mg_chacha20_poly1305_decrypt of the file /src/tls_chacha20.c of the component Poly1305 Authentication Tag Handler. The manipulation results in improper verification of cryptographic signature. The attack may be launched remotely. This attack is characterized by high complexity. The exploitability is said to be difficult. The exploit is now public and may be used. The vendor was contacted early about this di...
A security vulnerability has been detected in Cesanta Mongoose up to 7.20. This affects the function getpeer of the file /src/net_builtin.c of the component TCP Sequence Number Handler. [CVSS 3.7 LOW]
A weakness has been identified in Cesanta Mongoose up to 7.20. The impacted element is the function mg_sendnsreq of the file /src/dns.c of the component DNS Transaction ID Handler. [CVSS 3.7 LOW]
Null pointer dereference in add_ca_certs() in Cesanta Mongoose before 7.2 allows remote attackers to cause a denial of service via TLS initialization where SSL_CTX_get_cert_store() returns NULL. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
An integer overflow vulnerability exists in the WebSocket component of Mongoose 7.5 thru 7.17. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Improper Neutralization of Delimiters vulnerability in Cesanta Mongoose Web Server v7.14 allows to trigger an infinite loop bug if the input string contains unexpected characters. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and force the application to read unintended heap memory. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and force the application to read unintended heap memory. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and force the application to read unintended heap memory. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and force the application to read unintended heap memory. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and force the application to read unintended heap memory. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and produce a segmentation fault on the application. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Improper Neutralization of Delimiters vulnerability in Cesanta Mongoose Web Server v7.14 allows to trigger an out-of-bound memory write if the PEM certificate contains unexpected characters. Rated high severity (CVSS 7.0), this vulnerability is no authentication required. No vendor patch available.
Integer Overflow or Wraparound vulnerability in Cesanta Mongoose Web Server v7.14 allows an attacker to send an unexpected TLS packet and produce a segmentation fault on the application. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use of Out-of-range Pointer Offset vulnerability in Cesanta Mongoose Web Server v7.14 allows to write a NULL byte value beyond the memory space dedicated for the hostname field. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_do_gc function in the mjs.c file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_mk_ffi_sig function in the mjs.c file. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_array_length function in the mjs.c file. Rated medium severity (CVSS 5.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_destroy function in the msj.c file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An Out of Bounds Write in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_op_json_stringify function in the msj.c file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_op_json_parse function in the msj.c file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs+0x4ec508 component. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue in Cesanta mjs 2.20.0 allows a remote attacker to cause a denial of service via the mjs_getretvalpos function in the msj.c file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cesanta MJS 2.20.0 has a getprop_builtin_foreign out-of-bounds read if a Built-in API name occurs in a substring of an input string. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Cesanta mjs v2.20.0 was discovered to contain a function pointer hijacking vulnerability via the function mjs_get_ptr(). Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Due to a failure in validating the length of a provided MQTT_CMD_PUBLISH parsed message with a variable length header, Cesanta Mongoose, an embeddable web server, version 7.10 is susceptible to a. Rated high severity (CVSS 8.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
The HTTP server in Mongoose before 7.10 accepts requests containing negative Content-Length headers. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
An issue found in Cesanta MJS v.1.26 allows a local attacker to cause a denial of service via the mjs_execute function in mjs.c. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Buffer Overflow vulnerability found in Cesanta MJS v.1.26 allows a local attacker to cause a denial of service via the mjs_mk_string function in mjs.c. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Cesanta MJS v2.20.0 was discovered to contain a SEGV vulnerability via mjs_ffi_cb_free at src/mjs_ffi.c. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cesanta MJS v2.20.0 was discovered to contain a SEGV vulnerability via ffi_cb_impl_wpwwwww at src/mjs_ffi.c. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cesanta MJS v2.20.0 was discovered to contain a SEGV vulnerability via gc_sweep at src/mjs_gc.c. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
This affects the package cesanta/mongoose before 7.6. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
In mjs_json.c in Cesanta MongooseOS mJS 1.26, a maliciously formed JSON string can trigger an off-by-one heap-based buffer overflow in mjs_json_parse, which can potentially lead to redirection of. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 (compiled with OpenSSL support) is vulnerable to remote OOB write attack via connection request after exhausting memory pool. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 and 6.7-6.18 (compiled with mbedTLS support) is vulnerable to remote OOB write attack via connection request after exhausting memory pool. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
The mg_http_serve_file function in Cesanta Mongoose HTTP server 7.0 is vulnerable to remote OOB write attack via connection request after exhausting memory pool. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A buffer overflow vulnerability exists in the mg_get_http_header function in Cesanta Mongoose 6.18 due to a lack of bounds checking. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Buffer Copy without Size Check vulnerability could allow attackers to overflow a buffer to corrupt adjacent memory.
An integer overflow in parse_mqtt in mongoose.c in Cesanta Mongoose 6.16 allows an attacker to achieve remote DoS (infinite loop), or possibly cause an out-of-bounds write, by sending a crafted MQTT. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
mq_parse_http in mongoose.c in Mongoose 6.15 has a heap-based buffer over-read. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in Mongoose before 6.15. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Out-of-bounds Write vulnerability could allow attackers to write data beyond allocated buffer boundaries leading to code execution or crashes.
In Cesanta Mongoose 6.13, a SIGSEGV exists in the mongoose.c mg_mqtt_add_session() function. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An exploitable arbitrary memory read vulnerability exists in the MQTT packet-parsing functionality of Cesanta Mongoose 6.13. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An exploitable arbitrary memory read vulnerability exists in the MQTT packet-parsing functionality of Cesanta Mongoose 6.13. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
The mg_handle_cgi function in mongoose.c in Mongoose 6.11 allows remote attackers to cause a denial of service (heap-based buffer over-read and application crash, or NULL pointer dereference) via an. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An exploitable memory corruption vulnerability exists in the Websocket protocol implementation of Cesanta Mongoose 6.8. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An exploitable memory corruption vulnerability exists in the Websocket protocol implementation of Cesanta Mongoose 6.8. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An infinite loop programming error exists in the DNS server functionality of Cesanta Mongoose 6.8 library. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An exploitable arbitrary memory read vulnerability exists in the MQTT packet parsing functionality of Cesanta Mongoose 6.8. Rated high severity (CVSS 8.2), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An exploitable stack buffer overflow vulnerability exists in the MQTT packet parsing functionality of Cesanta Mongoose 6.8. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An exploitable NULL pointer dereference vulnerability exists in the MQTT packet parsing functionality of Cesanta Mongoose 6.8. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An exploitable arbitrary memory read vulnerability exists in the MQTT packet parsing functionality of Cesanta Mongoose 6.8. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An exploitable use-after-free vulnerability exists in the HTTP server implementation of Cesanta Mongoose 6.8. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cross-site request forgery (CSRF) vulnerability in Mongoose Web Server before 6.9 allows remote attackers to hijack the authentication of users for requests that modify Mongoose.conf via a request to. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Use-after-free vulnerability in the mg_http_multipart_wait_for_boundary function in mongoose.c in Cesanta Mongoose Embedded Web Server Library 6.7 and earlier and Mongoose OS 1.2 and earlier allows. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and EPSS exploitation probability 33.2%.