CVE Catalog

CVE-2025-21637

HighCVSS 7.1
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.21%

11th percentile - higher than 11% of all known CVEs

Summary

In the Linux kernel, in the SCTP subsystem, a vulnerability was found in the sysctl handler for UDP port, which uses the 'current->nsproxy' structure. This can lead to a null-pointer dereference (Oops) when the current process is exiting, potentially exploited by an attacker to cause a system crash.

Risk Assessment

The risk is the possibility of causing a system crash (kernel panic) by deliberately triggering a scenario where 'current->nsproxy' is NULL, which may lead to service disruption or data loss.

Recommendation

It is recommended to immediately update the Linux kernel to a version containing the fix, which obtains the 'net' structure from 'table->data' instead of 'current->nsproxy'.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: sctp: sysctl: udp_port: avoid using current->nsproxy As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, but that would increase the size of this fix, while 'sctp.ctl_sock' still needs to be retrieved from 'net' structure.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS