CVE-2023-1281
kernel: tcindex: use-after-free vulnerability in traffic control index filter allows privilege escalation
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · February 23, 2023
Updated · July 31, 2026
Description
A use-after-free vulnerability was found in the traffic control index filter (tcindex) in the Linux kernel. The imperfect hash area can be updated while packets are traversing. This issue could allow a local attacker to cause a use-after-free problem, leading to privilege escalation.
Statement
For the Red Hat Enterprise Linux 7, please use mitigation to disable module cls_tcindex, because some other bugs exists in the Linux Kernel traffic control index filter too that not going to be fixed before Red Hat Enterprise Linux 8.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
This flaw can be mitigated by preventing the affected traffic control index filter (cls_tcindex) kernel module from loading during the boot time, ensure the module is added into the blacklist file.
Refer:
How do I blacklist a kernel module to prevent it from loading automatically?
https://access.redhat.com/solutions/41278
CVSS / CWE
CVSS 3.1 · 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-416 · Use After Free