CVE-2025-21789: linux kernel Out-of-bounds Read — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: LoongArch: csum: Fix OoB access in IP checksum code for negative lengths Commit 69e3a6aa6be2 ("LoongArch: Add checksum optimization for 64-bit system") would cause an undefined shift and an out-of-bounds read. Commit 8bd795fedb84 ("arm64: csum: Fix OoB access in IP checksum code for negative lengths") fixes the same issue on ARM64.

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CVSS v3.1 Score

7.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

Affected Products

Vendor	Product	Versions
linux	linux_kernel	6.4 — 6.6.79
linux	linux_kernel	6.7 — 6.12.16
linux	linux_kernel	6.13 — 6.13.4
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/6287f1a8c16138c2ec750953e35039634018c84a https://git.kernel.org/stable/c/964a8895704a22efc06a2a3276b624a5ae985a06 https://git.kernel.org/stable/c/9f15a8df542c0f08732a67d1a14ee7c22948fb97 https://git.kernel.org/stable/c/d6508ffff32b44b6d0de06704034e4eef1c307a7

Frequently Asked Questions

What is CVE-2025-21789? +

In the Linux kernel, the following vulnerability has been resolved: LoongArch: csum: Fix OoB access in IP checksum code for negative lengths Commit 69e3a6aa6be2 ("LoongArch: Add checksum optimization for 64-bit system") would cause an undefined shift and an out-of-bounds read. Commit 8bd795fedb84 ("arm64: csum: Fix OoB access in IP checksum code for negative lengths") fixes the same issue on ARM64. It has a CVSS v3.1 base score of 7.1 (HIGH).

How severe is CVE-2025-21789? +

CVE-2025-21789 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-21789? +

CVE-2025-21789 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-21789? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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