Use After Free in Linux Kernel
CVE-2023-4206
A use-after-free vulnerability in the Linux kernel's net/sched: cls_route component can be exploited to achieve local privilege escalation. When route4_change() is called on an existing filter, the whole tcf_result struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcf_unbind_filter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free. We recommend upgrading past commit b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8.
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: 0.006 (46.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Linux Kernel — versions 3.18
- Linux Kernel
- Debian Linux — versions 12.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/ (Patch, Mailing List, patch, Issue Tracking, Vendor Advisory)
- kernel.dance/b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8 (Patch, Vendor Advisory)
- www.debian.org/security/2023/dsa-5492 (Third Party Advisory)
- lists.debian.org/debian-lts-announce/2024/01/msg00004.html (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2023-4206?
- CVE-2023-4206 is a high-severity vulnerability in Linux Kernel, classified under Use After Free. CVSS score: 7.8/10. Published 2023-09-06.
- How severe is CVE-2023-4206?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2023-4206 known to be exploited?
- 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.