CVE-2025-69217 Coturn has unsafe nonce and relay port randomization due to weak random number generation.
Weak random number generation allows attackers to predict nonces and relay ports, enabling authentication bypass and traffic interception in coturn servers.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-69217?
CVE-2025-69217 is a high-severity vulnerability in coturn, published on 30 Dec 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
coturn is a free open source implementation of TURN and STUN Server. Versions 4.6.2r5 through 4.7.0-r4 have a bad random number generator for nonces and port randomization after refactoring. Additionally, random numbers aren't generated with openssl's RAND_bytes but libc's random() (if it's not running on Windows). When fetching about 50 sequential nonces (i.e., through sending 50 unauthenticated allocations requests) it is possible to completely reconstruct the current state of the random number generator, thereby predicting the next nonce. This allows authentication while spoofing IPs. An attacker can send authenticated messages without ever receiving the responses, including the nonce (requires knowledge of the credentials, which is e.g., often the case in IoT settings). Since the port randomization is deterministic given the pseudorandom seed, an attacker can exactly reconstruct the ports and, hence predict the randomization of the ports. If an attacker allocates a relay port, they know the current port, and they are able to predict the next relay port (at least if it is not used before). Commit 11fc465f4bba70bb0ad8aae17d6c4a63a29917d9 contains a fix.
Weakness: CWE-338
Which versions are affected by CVE-2025-69217?
How do I fix CVE-2025-69217?
Apply the vendor's patch.
Is CVE-2025-69217 being exploited?
There is no known exploitation of CVE-2025-69217 in the wild and no public exploit code.
Sources
Also known as GHSA-fvj6-9jhg-9j84, UBUNTU-CVE-2025-69217.