CVE-2023-0266: Linux Kernel Use-After-Free Vulnerability

Vulnerability summary

CVE-2023-0266 is a high (CVSS 7.9) Use After Free vulnerability in Linux Kernel. It is known to be exploited: CISA lists it, first on 30-03-2023. EPSS estimates a 3.70% chance of exploitation in the next 30 days, higher than 89.7% of scored vulnerabilities.

Timeline

1. 30-01-2023
   PublishedVulnerability first disclosed.
2. 30-03-2023
   Added to CISA KEVExploitedLinux Kernel Use-After-Free Vulnerability
3. 20-04-2023
   CISA remediation dueDeadline passedApply updates per vendor instructions.
4. 21-10-2025
   Last modifiedVulnerability information updated.

Description

A use after free vulnerability exists in the ALSA PCM package in the Linux Kernel. SNDRV_CTL_IOCTL_ELEM_{READ|WRITE}32 is missing locks that can be used in a use-after-free that can result in a priviledge escalation to gain ring0 access from the system user. We recommend upgrading past commit 56b88b50565cd8b946a2d00b0c83927b7ebb055e

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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.