CVE-2023-4622: Use-after-free in Linux kernel's af_unix component

Vulnerability summary

CVE-2023-4622 is a high (CVSS 7.8) Use After Free vulnerability in debian debian_linux. EPSS estimates a 0.62% chance of exploitation in the next 30 days, higher than 49.6% of scored vulnerabilities.

Timeline

1. 06-09-2023
   PublishedVulnerability first disclosed.
2. 17-09-2026
   Last modifiedVulnerability information updated.

Description

A use-after-free vulnerability in the Linux kernel's af_unix component can be exploited to achieve local privilege escalation. The unix_stream_sendpage() function tries to add data to the last skb in the peer's recv queue without locking the queue. Thus there is a race where unix_stream_sendpage() could access an skb locklessly that is being released by garbage collection, resulting in use-after-free. We recommend upgrading past commit 790c2f9d15b594350ae9bca7b236f2b1859de02c (or backported equivalents).

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.