Use After Free in Linux Kernel
CVE-2023-4921
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.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (34.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000
Affected products
- Linux Kernel — versions 3.8
- Linux Kernel
- Debian Linux — versions 10.0
Weakness classification (CWE)
References
- git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/ (Exploit, Patch, Mailing List, patch, Vendor Advisory)
- kernel.dance/8fc134fee27f2263988ae38920bc03da416b03d8 (Exploit, Patch, Vendor Advisory)
- lists.debian.org/debian-lts-announce/2023/10/msg00027.html (Mailing List, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2024/01/msg00004.html (Mailing List, Third Party Advisory)
- 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
- 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
- 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
Frequently asked questions
- What is CVE-2023-4921?
- CVE-2023-4921 is a high-severity vulnerability in Linux Kernel, classified under Use After Free. CVSS score: 7.8/10. Published 2023-09-12.
- How severe is CVE-2023-4921?
- High severity. CVSS v3 base score is 7.8 out of 10.