Libcoap
CVE-2025-34468
HIGH
Severity by source
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Primary rating from Vendor (vulncheck) · only source for this CVE.
CVSS VectorVendor: vulncheck
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
3DescriptionCVE.org
libcoap versions up to and including 4.3.5, prior to commit 30db3ea, contain a stack-based buffer overflow in address resolution when attacker-controlled hostname data is copied into a fixed 256-byte stack buffer without proper bounds checking. A remote attacker can trigger a crash and potentially achieve remote code execution depending on compiler options and runtime memory protections. Exploitation requires the proxy logic to be enabled (i.e., the proxy request handling code path in an application using libcoap).
AnalysisAI
Availability loss and potential remote code execution in libcoap (versions up to and including 4.3.5, before commit 30db3ea) arises when attacker-controlled hostname data from a proxied CoAP URI is copied into a fixed 256-byte stack buffer during address resolution without bounds checking. A remote unauthenticated attacker can reliably crash any application that enables libcoap's proxy request handling, and may achieve code execution depending on the target's compiler hardening and runtime memory protections. There is no public exploit identified at time of analysis and it is not listed in CISA KEV; the official CVSS 4.0 base score is 8.2, but that score reflects availability impact only (VA:H, VC:N/VI:N).
A vulnerability was found in obgm libcoap 4.3.4. Rated high severity (CVSS 7.8), this vulnerability is low attack comple
An issue in `coap_pdu.c` in libcoap 4.3.4 allows attackers to cause undefined behavior via a sequence of messages leadin
Buffer Overflow vulnerability in coap_send function in libcoap library 4.3.1-103-g52cfd56 fixed in 4.3.1-120-ge242200 al
libcoap 4.3.1 contains a buffer over-read via the function coap_parse_oscore_conf_mem at coap_oscore.c. Rated medium sev
Out-of-bounds read in libcoap's OSCORE CBOR parsing can escalate to heap buffer overflow, enabling remote unauthenticate
A memory disclosure vulnerability exists in libcoap's OSCORE configuration parser in libcoap before release-4.3.5-patche
Null pointer dereference in coap_dtls_info_callback() in OISM libcoap 4.3.5 allows remote attackers to cause a denial of
NULL pointer dereference in coap_dtls_generate_cookie() in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attack
Array index error in tls_verify_call_back() in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attackers to cause
NULL pointer dereference in coap_dtls_generate_cookie() in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attack
NULL pointer dereference in coap_dtls_generate_cookie() in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attack
NULL pointer dereference in coap_dtls_generate_cookie() in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attack
Same weakness CWE-121 – Stack-based Buffer Overflow
View allSame technique Buffer Overflow
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External POC / Exploit Code
Leaving vuln.today