Vulnerabilities > CVE-2023-4207 - Use After Free vulnerability in multiple products
Summary
A use-after-free vulnerability in the Linux kernel's net/sched: cls_fw component can be exploited to achieve local privilege escalation. When fw_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 76e42ae831991c828cffa8c37736ebfb831ad5ec.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
References
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76e42ae831991c828cffa8c37736ebfb831ad5ec
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76e42ae831991c828cffa8c37736ebfb831ad5ec
- https://kernel.dance/76e42ae831991c828cffa8c37736ebfb831ad5ec
- https://kernel.dance/76e42ae831991c828cffa8c37736ebfb831ad5ec
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html
- https://www.debian.org/security/2023/dsa-5492
- https://www.debian.org/security/2023/dsa-5492