PT-2025-14339 · Linux+2 · Linux Kernel+2

Published 2025-03-08 · Updated 2026-01-20 · CVE-2025-21958

Positive Technologies (AI Summary)

CVSS v3.1

4.7

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The issue is related to the openvswitch in the Linux kernel. Specifically, it involves the ovs ct set labels() function, which is called for confirmed conntrack entries within ovs ct commit(). However, if a conntrack entry does not have the labels ext extension, attempting to allocate it in ovs ct get conn labels() for a confirmed entry triggers a warning in nf ct ext add(). This warning occurs when the conntrack entry is created externally before OVS increments net->ct.labels used. The problem has become more likely since the commit that changed to use per-action label counting and increment net->ct.labels used when a flow with ct action is added. The issue has been mitigated by reverting this commit to avoid breaking existing use cases.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Allocation of Resources Without Limits

Time Of Check To Time Of Use

Weakness Enumeration

CWE-770

CWE-367

Related Identifiers

BDU:2025-12299

CVE-2025-21958

Affected Products

Astra Linux

Linux Kernel

Red Os

References · 24

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21958.json · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2025-21958 · Security Note
• http://repo.red-soft.ru/redos/8.0/x86_64/updates · Vendor Advisory
• https://bdu.fstec.ru/vul/2025-12299 · Security Note
• https://git.kernel.org/stable/c/d91bfc64a4886102746e74d2c6f3a61e9a77fd7d · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2025-21958 · Vendor Advisory
• https://linux.oracle.com/errata/ELSA-2025-20480.html · Vendor Advisory
• https://git.kernel.org/stable/c/9e79fdabd52cfce1a021640a81256878a2c516a2 · Patch
• https://ubuntu.com/security/CVE-2025-21958 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2025-21958 · Vendor Advisory
• https://git.kernel.org/stable/c/1063ae07383c0ddc5bcce170260c143825846b03 · Patch
• https://cve.org/CVERecord?id=CVE-2025-21958 · Security Note
• https://linux.oracle.com/errata/ELSA-2025-20530.html · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2025-21958 · Vendor Advisory
• https://osv.dev/vulnerability/BELL-CVE-2025-21958 · Vendor Advisory