CVE-2023-4921
Use-after-free in Linux kernel's net/sched: sch_qfq component
- State
- Published
- Severity
- 7.8 High
- Published
- Sep 12, 2023
- Updated
- Oct 14, 2026
- Reserved
- Sep 12, 2023
Description
A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation.
When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue().
We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.8 High | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Weaknesses
- CWE-416 Use After Free
Affected Products
| Product | Versions |
|---|---|
KernelLinux |
|
References
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8fc134fee27f2263988ae38920bc03da416b03d8patch
- https://kernel.dance/8fc134fee27f2263988ae38920bc03da416b03d8
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html
- https://cert-portal.siemens.com/productcert/html/ssa-794697.html
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html
- https://cert-portal.siemens.com/productcert/html/ssa-769027.html
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