CVE-2025-15468: NULL dereference in SSL_CIPHER_find() function on unknown cipher ID
A NULL pointer dereference leads to abnormal termination of the running process causing Denial of Service.
Some applications call SSLCIPHERfind() from the clienthellocb callback on the cipher ID received from the peer. If this is done with an SSL object implementing the QUIC protocol, NULL pointer dereference will happen if the examined cipher ID is unknown or unsupported.
As it is not very common to call this function in applications using the QUIC protocol and the worst outcome is Denial of Service, the issue was assessed as Low severity.
The vulnerable code was introduced in the 3.2 version with the addition of the QUIC protocol support.
The FIPS modules in 3.6, 3.5, 3.4 and 3.3 are not affected by this issue, as the QUIC implementation is outside the OpenSSL FIPS module boundary.
OpenSSL 3.6, 3.5, 3.4 and 3.3 are vulnerable to this issue.
OpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.
OpenSSL 3.6 users should upgrade to OpenSSL 3.6.1.
OpenSSL 3.5 users should upgrade to OpenSSL 3.5.5.
OpenSSL 3.4 users should upgrade to OpenSSL 3.4.4.
OpenSSL 3.3 users should upgrade to OpenSSL 3.3.6.
Other sources
Issue summary: If an application using the SSLCIPHERfind() function in a QUIC protocol client or server receives an unknown cipher suite from the peer, a NULL dereference occurs.
Impact summary: A NULL pointer dereference leads to abnormal termination of the running process causing Denial of Service.
Some applications call SSLCIPHERfind() from the clienthellocb callback on the cipher ID received from the peer. If this is done with an SSL object implementing the QUIC protocol, NULL pointer dereference will happen if the examined cipher ID is unknown or unsupported.
As it is not very common to call this function in applications using the QUIC protocol and the worst outcome is Denial of Service, the issue was assessed as Low severity.
The vulnerable code was introduced in the 3.2 version with the addition of the QUIC protocol support.
The FIPS modules in 3.6, 3.5, 3.4 and 3.3 are not affected by this issue, as the QUIC implementation is outside the OpenSSL FIPS module boundary.
OpenSSL 3.6, 3.5, 3.4 and 3.3 are vulnerable to this issue.
OpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
OpenSSLto a version that resolves this vulnerability.Fixed in 3.3.6 - Upgrade
Upgrade
OpenSSLto a version that resolves this vulnerability.Fixed in 3.4.4 - Upgrade
Upgrade
OpenSSLto a version that resolves this vulnerability.Fixed in 3.5.5 - Upgrade
Upgrade
OpenSSLto a version that resolves this vulnerability.Fixed in 3.6.1
Event History
Frequently Asked Questions
What is the severity of CVE-2025-15468?
CVE-2025-15468 is classified as a Denial of Service vulnerability due to a NULL pointer dereference.
How do I fix CVE-2025-15468?
To remediate CVE-2025-15468, upgrade to a patched version of OpenSSL that addresses this NULL dereference issue.
What software is affected by CVE-2025-15468?
CVE-2025-15468 affects OpenSSL versions between 3.2 and 3.6.
What causes the CVE-2025-15468 vulnerability?
The vulnerability is caused by a NULL pointer dereference in the SSL_CIPHER_find() function when called with an unknown cipher ID.
What are the potential consequences of exploiting CVE-2025-15468?
Exploiting CVE-2025-15468 can lead to the abnormal termination of the running process, resulting in a Denial of Service.