Bug 2425955 (CVE-2025-69217)

Summary: CVE-2025-69217 coturn: coturn: Authentication bypass and port prediction via predictable random number generation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedCC: redhat-bugzilla
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in coturn. A remote attacker can exploit a predictable random number generator used for nonces and port randomization. By sending a series of unauthenticated requests, an attacker can reconstruct the random number generator's state, allowing them to predict future nonces and port assignments. This vulnerability enables authentication bypass with spoofed IP addresses and the ability to predict relay ports, potentially leading to unauthorized access or denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2425968, 2425969, 2425970, 2425971, 2425972    
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Description OSIDB Bzimport 2025-12-30 02:01:36 UTC 
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.