CVE-2023-2236: linux linux_kernel Use After Free

Vulnerability summary

CVE-2023-2236 is a high (CVSS 7.8) Use After Free vulnerability in linux linux_kernel. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 35.7% of scored vulnerabilities. 2 public exploits are recorded.

Timeline

1. 01-05-2023
   PublishedVulnerability first disclosed.
2. 05-03-2025
   Last modifiedVulnerability information updated.

Description

A use-after-free vulnerability in the Linux Kernel io_uring subsystem can be exploited to achieve local privilege escalation. Both io_install_fixed_file and its callers call fput in a file in case of an error, causing a reference underflow which leads to a use-after-free vulnerability. We recommend upgrading past commit 9d94c04c0db024922e886c9fd429659f22f48ea4.

• 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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.