Coturn Project: >> Coturn >> 4.9.0 Security Vulnerabilities
Coturn is a free open source implementation of TURN and STUN Server. Versions prior to 4.10.0 contain a stack buffer overflow in decode_oauth_token_gcm(). A uint16_t nonce_len field read from an attacker-supplied OAuth access token (0-65535) is passed directly to memcpy() as the copy length into a 256-byte stack buffer (oauth_encrypted_block.nonce[256]) without bounds checking. The overflow occurs before AES-GCM authentication is verified, the attacker does not need to know the OAuth key or produce a valid AES-GCM token. Up to 735 bytes of attacker-controlled data are written past the buffer, may corrupt adjacent stack data, including control-flow data depending on compiler, ABI, and mitigations. Requires --oauth mode (non-default). This may provide a plausible RCE primitive depending on exploit mitigations; because coturn is widely deployed for WebRTC TURN/STUN and --oauth is commonly recommended, impact can be broad. This issue has been fixed in version 4.10.0.
CVSS Score
8.1
EPSS Score
0.004
Published
2026-06-18
Coturn is a free open source implementation of TURN and STUN Server. Versions prior to 4.11.0 contain a stored cross-site scripting (XSS) vulnerability in the web-admin HTTPS interface. An attacker who can create a TURN allocation with a crafted USERNAME value can inject HTML/JavaScript that executes when an authenticated web-admin user views the TURN session list. In configurations using anonymous TURN access (--no-auth), this may be exploitable without TURN credentials. In authenticated deployments, exploitation requires valid TURN credentials or control over a provisioned username. This issue has been fixed in version 4.11.0.
CVSS Score
5.4
EPSS Score
0.001
Published
2026-06-18
Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.10.0, the STUN/TURN attribute parsing functions in coturn perform unsafe pointer casts from uint8_t * to uint16_t * without alignment checks. When processing a crafted STUN message with odd-aligned attribute boundaries, this results in misaligned memory reads at ns_turn_msg.c. On ARM64 architectures (AArch64) with strict alignment enforcement, this causes a SIGBUS signal that immediately kills the turnserver process. An unauthenticated remote attacker can crash any ARM64 coturn deployment by sending a single crafted UDP packet. This vulnerability is fixed in 4.10.0.
CVSS Score
7.5
EPSS Score
0.011
Published
2026-04-21