CVE-2023-1872: Use-after-free in Linux kernel's io_uring subsystem

Vulnerability summary

CVE-2023-1872 is a high (CVSS 7.8) Use After Free vulnerability in debian debian_linux. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 23.5% of scored vulnerabilities.

Timeline

1. 12-04-2023
   PublishedVulnerability first disclosed.
2. 13-02-2025
   Last modifiedVulnerability information updated.

Description

A use-after-free vulnerability in the Linux Kernel io_uring system can be exploited to achieve local privilege escalation. The io_file_get_fixed function lacks the presence of ctx->uring_lock which can lead to a Use-After-Free vulnerability due a race condition with fixed files getting unregistered. We recommend upgrading past commit da24142b1ef9fd5d36b76e36bab328a5b27523e8.

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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.