Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.16.0, dtls_server_input_handler() and create_new_connected_udp_socket() in src/apps/relay/dtls_listener.c retain OpenSSL dtls1_reassemble_fragment() state for a 35-byte fragmented ClientHello declaring a 650,000-byte handshake before cookie validation, allowing an unauthenticated remote sender using fresh UDP tuples to exhaust memory without TURN credentials, a completed handshake, a valid cookie, or source spoofing. This issue is fixed in version 4.16.0.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 6
https://github.com/coturn/coturn/commit/37e13d1d60af8f1422c01b5e9f1c6bc355d03b85
security-advisories@github.com
https://github.com/coturn/coturn/commit/beb4de9dcb6a475129595b943c9a34264420df09
security-advisories@github.com
https://github.com/coturn/coturn/pull/2003
security-advisories@github.com
https://github.com/coturn/coturn/pull/2012
security-advisories@github.com
https://github.com/coturn/coturn/releases/tag/4.16.0
security-advisories@github.com
https://github.com/coturn/coturn/security/advisories/GHSA-5x2p-4vqj-f6m4
security-advisories@github.com