Coturn

Memory exhaustion in Coturn 4.15.0 allows an authenticated TURN user to crash or degrade server availability by abusing the RFC 8016 mobility extension (--mobility). The attacker repeatedly resumes a single TURN allocation from fresh UDP 5-tuples without completing handoffs, which overwrites the allocation's sole mobile_pending_resume backlink and orphans prior pending sessions whose cleanup watchdogs have been disarmed - causing unbounded process memory growth. No public exploit has been identified at time of analysis, though the patch commit includes a Python regression script (mobility_resume_flood.py) that precisely models the attack pattern, serving as an effective blueprint; exploitation requires both --mobility to be enabled and valid authenticated TURN credentials.

TCP/TLS stream parser desynchronization in Coturn TURN/STUN server prior to 4.15.0 allows any unauthenticated remote client to crash their own connection by sending a STUN message with a crafted body-length field value between 65520 and 65532. The integer overflow in stun_get_message_len_str() causes the framing layer to misinterpret the stream, consuming only 4-16 bytes and treating remaining data as a new message, ultimately dropping the attacking client's connection. No other clients or the server process are impacted; vendor-released patch version 4.15.0 is available and no active exploitation is confirmed.

Coturn STUN/TURN server prior to version 4.15.0 allows an on-path attacker to tamper with authenticated STUN messages over plain UDP or TCP by appending arbitrary attributes after the MESSAGE-INTEGRITY field and recomputing the unkeyed FINGERPRINT. Because Coturn's server-side attribute iterator did not stop at the MESSAGE-INTEGRITY boundary as required by RFC 8489 Section 9, injected LIFETIME, XOR-PEER-ADDRESS, or ORIGIN attributes were processed as legitimate, enabling allocation lifetime manipulation, unauthorized permission injection, or origin-check bypass. TLS and DTLS deployments are entirely unaffected; no public exploit has been identified at time of analysis.

Format string injection in Coturn prior to 4.13.0 lets an authenticated TURN user crash the relay server or leak stack memory into Redis by embedding printf-style specifiers in STUN USERNAME or REALM attributes. At nine call sites in ns_ioalib_engine_impl.c, attacker-controlled values pass is_secure_string() validation and are embedded into Redis keys; send_message_to_redis() then passes the composite key as the format argument to redisAsyncCommand(), causing redisvFormatCommand() to read past the va_list. No public exploit identified at time of analysis and no CISA KEV listing; however, the attack surface is reachable by any valid TURN credential holder, including guest or externally-provisioned users in many WebRTC deployments.

Server-side request forgery in coturn TURN/STUN server before 4.13.0 lets an authenticated TURN client bypass the default loopback-peer guard by supplying the IPv4-mapped IPv6 address ::ffff:127.0.0.1 in the XOR-PEER-ADDRESS attribute, relaying traffic to services bound only to the coturn host's localhost. The loopback check evaluates the literal IPv6 loopback shape before IPv4-mapped IPv6 normalization, so good_peer_addr never applies the rejection even when allow-loopback-peers is disabled. No public exploit identified at time of analysis and it is not listed in CISA KEV, but the fix is confirmed in version 4.13.0.

Arbitrary file overwrite in Coturn prior to 4.13.0 is possible through the CLI management interface's `psd` (print sessions dump) command, which passes a user-supplied filename directly to `fopen()` without any path validation (CWE-73). An authenticated admin with CLI access can overwrite any file writable by the coturn process, potentially corrupting sensitive system files, certificates, or configuration data to achieve privilege escalation or service disruption. No public exploit identified at time of analysis; exploitation is constrained to local, high-privilege access, limiting realistic threat surface despite the High integrity and availability impact ratings.

SQL injection in the Coturn TURN/STUN server's HTTPS admin panel (versions prior to 4.12.0) allows an authenticated administrator to inject arbitrary SQL via the du, ds, and dip query parameters of the delete-user, delete-secret, and delete-IP operations, yielding full backend database control and, on PostgreSQL deployments, OS-level command execution through COPY TO PROGRAM. The admin panel's parameters are interpolated into queries with snprintf while bypassing the is_secure_string filter that guards the STUN protocol path. No public exploit is identified at time of analysis and the flaw is not listed in CISA KEV; fixed in Coturn 4.12.0.

Stack buffer overflow in Coturn's OAuth token decoder (decode_oauth_token_gcm()) lets remote unauthenticated attackers corrupt the server stack in all versions prior to 4.10.0. An attacker-controlled uint16_t nonce_len value (up to 65535) read from an OAuth access token is passed straight into memcpy() against a 256-byte stack buffer before any AES-GCM authentication, so no OAuth key or valid token is required to write up to 735 bytes past the buffer. Publicly available exploit code exists (SSVC: PoC) but it is not in CISA KEV, EPSS is low at 0.36% (27th percentile), and exploitation is gated on the non-default --oauth mode being enabled.

Stored XSS in Coturn's web-admin HTTPS interface (all versions prior to 4.11.0) allows a TURN-level attacker to inject persistent JavaScript that executes in an authenticated administrator's browser when they view the session list. The attack is staged via a crafted USERNAME value in a TURN Allocate request, bridging the TURN protocol surface into the web-admin UI context. In anonymous deployments (--no-auth), no TURN credentials are required for the injection phase, broadening the exposure; in authenticated deployments the attacker must hold valid TURN credentials. No public exploit has been identified and this vulnerability is not listed in CISA KEV.

Remote denial of service in Coturn TURN/STUN server allows unauthenticated attackers to crash ARM64 deployments with a single malformed UDP packet. The vulnerability triggers a fatal SIGBUS signal via misaligned memory access during STUN attribute parsing, requiring no authentication or special configuration. All ARM64 installations of Coturn prior to 4.10.0 are vulnerable to instant process termination. EPSS exploitation probability is not yet available as this is a newly disclosed CVE, but the attack complexity is low (AC:L) and requires no privileges (PR:N), making exploitation trivial once awareness spreads in attacker communities.

Coturn TURN/STUN server contains an access control bypass that allows remote attackers to reach blocked internal addresses by exploiting IPv4-mapped IPv6 address handling in permission and channel binding requests. The vulnerability bypasses "denied-peer-ip" restrictions designed to block loopback ranges, enabling an attacker to interact with internal services that should be unreachable. Public exploit code exists for this flaw, and a patch is available in version 4.9.0 and later.

In coturn before version 4.5.1.3, there is an issue whereby STUN/TURN response buffer is not initialized properly. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

An exploitable denial-of-service vulnerability exists in the way CoTURN 4.5.1.1 web server parses POST requests. 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 heap out-of-bounds read vulnerability exists in the way CoTURN 4.5.1.1 web server parses POST requests. 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.