CVE-2025-21691
5.5 · MEDIUMOverview
CVE-2025-21691 is a medium-severity vulnerability affecting linux linux_kernel. It was published on February 10, 2025 and has a CVSS 3.1 base score of 5.5 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. 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:
cachestat: fix page cache statistics permission checking
When the 'cachestat()' system call was added in commit cf264e1329fb
("cachestat: implement cachestat syscall"), it was meant to be a much
more convenient (and performant) version of mincore() that didn't need
mapping things into the user virtual address space in order to work.
But it ended up missing the "check for writability or ownership" fix for
mincore(), done in commit 134fca9063ad ("mm/mincore.c: make mincore()
more conservative").
This just adds equivalent logic to 'cachestat()', modified for the file
context (rather than vma).
Remediation
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. 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.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| linux | linux_kernel | >= 6.5, < 6.6.75 | Affected |
Frequently Asked Questions
What is CVE-2025-21691?
CVE-2025-21691 is a medium-severity vulnerability affecting linux linux_kernel. It was published on February 10, 2025 and has a CVSS 3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2025-21691?
This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2025-21691?
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. 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-2025-21691?
CyberStrike's AI-powered security agents can automatically detect CVE-2025-21691 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
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