CVE-2025-21703

HIGH EPSS 19.3%
Published Feb 18, 20251y ago · Modified Jun 17, 20261w ago
7.8 CVSS 3.1
High
Find Similar
Published Feb 18, 2025 1y ago
Last Modified Jun 17, 2026 1w ago

Description

In the Linux kernel, the following vulnerability has been resolved: netem: Update sch->q.qlen before qdisc_tree_reduce_backlog() qdisc_tree_reduce_backlog() notifies parent qdisc only if child qdisc becomes empty, therefore we need to reduce the backlog of the child qdisc before calling it. Otherwise it would miss the opportunity to call cops->qlen_notify(), in the case of DRR, it resulted in UAF since DRR uses ->qlen_notify() to maintain its active list.

CVSS Details

Base Score
7.8
Exploitability
1.8
Impact
5.9
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
19.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-416 Use After Free Memory Safety

Affected Products 8

VendorProductVersionRange
linuxlinux_kernel*≥5.4.288  –  <5.4.291
linuxlinux_kernel*≥5.10.232  –  <5.10.235
linuxlinux_kernel*≥5.15.175  –  <5.15.179
linuxlinux_kernel*≥6.1.121  –  <6.1.129
linuxlinux_kernel*≥6.6.67  –  <6.6.78
linuxlinux_kernel*≥6.12.6  –  <6.12.14
linuxlinux_kernel*≥6.13  –  <6.13.3
linuxlinux_kernel6.14any

References 9

  • git.kernel.org https://git.kernel.org/stable/c/1f8e3f4a4b8b90ad274dfbc66fc7d55cb582f4d5
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6312555249082d6d8cc5321ff725df05482d8b83
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/638ba5089324796c2ee49af10427459c2de35f71
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7b79ca9a1de6a428d486ff52fb3d602321c08f55
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7f31d74fcc556a9166b1bb20515542de7bb939d1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/839ecc583fa00fab785fde1c85a326743657fd32
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/98a2c685293aae122f688cde11d9334dddc5d207
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e395fec75ac2dbffc99b4bce57b7f1f3c5449f2c
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/1f8e3f4a4b8b90ad274dfbc66fc7d55cb582f4d5
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6312555249082d6d8cc5321ff725df05482d8b83
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/638ba5089324796c2ee49af10427459c2de35f71
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7b79ca9a1de6a428d486ff52fb3d602321c08f55
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7f31d74fcc556a9166b1bb20515542de7bb939d1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/839ecc583fa00fab785fde1c85a326743657fd32
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/98a2c685293aae122f688cde11d9334dddc5d207
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e395fec75ac2dbffc99b4bce57b7f1f3c5449f2c
    Patch