Go to homepageCyberStrike

Menu

Star on GitHub · 3.2k
Sign inDownload

CVE-2025-21640

7.1 · HIGH

In the Linux kernel, the following vulnerability has been resolved: sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy As mentioned in a previous commit of this series, using the 'net' s…

Published Jan 19, 2025CWE-476EPSS 0.24%

Overview

CVE-2025-21640 is a high-severity vulnerability. It was published on January 19, 2025 and has a CVSS 3.1 base score of 7.1 (HIGH).

This vulnerability has a CVSS 3.1 base score of 7.1, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.

Technical description

In the Linux kernel, the following vulnerability has been resolved:

sctp: sysctl: cookie_hmac_alg: 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, as this is the only

member needed from the 'net' structure, but that would increase the size

of this fix, to use '*data' everywhere 'net->sctp.sctp_hmac_alg' is

used.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

Refgit.kernel.org/stable/c/03ca51faba2b017bf6c90e139434c4117d0afcdcRefgit.kernel.org/stable/c/3cd0659deb9c03535fd61839e91d4d4d3e51ac71Refgit.kernel.org/stable/c/5599b212d2f4466e1832a94e9932684aaa364587Refgit.kernel.org/stable/c/86ddf8118123cb58a0fb8724cad6979c4069065bRefgit.kernel.org/stable/c/ad673e514b2793b8d5902f6ba6ab7e890dea23d5Refgit.kernel.org/stable/c/ea62dd1383913b5999f3d16ae99d411f41b528d4Refgit.kernel.org/stable/c/f0bb3935470684306e4e04793a20ac4c4b08de0bReflists.debian.org/debian-lts-announce/2025/03/msg00001.htmlReflists.debian.org/debian-lts-announce/2025/03/msg00002.htmlRefcert-portal.siemens.com/productcert/html/ssa-265688.html

How CyberStrike helps

Frequently asked questions

What is CVE-2025-21640?

CVE-2025-21640 is a high-severity vulnerability. It was published on January 19, 2025 and has a CVSS 3.1 base score of 7.1 (HIGH).

How severe is CVE-2025-21640?

This vulnerability has a CVSS 3.1 base score of 7.1, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.

How do I fix or remediate CVE-2025-21640?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2025-21640?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2025-21640 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related HIGH CVEs from 2025

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999