CVE-2023-4911 vulnerability in Canonical and Other Products
Published on October 3, 2023

A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBC_TUNABLES environment variable. This issue could allow a local attacker to use maliciously crafted GLIBC_TUNABLES environment variables when launching binaries with SUID permission to execute code with elevated privileges.

NVD

Known Exploited Vulnerability

This GNU C Library Buffer Overflow Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. GNU C Library's dynamic loader ld.so contains a buffer overflow vulnerability when processing the GLIBC_TUNABLES environment variable, allowing a local attacker to execute code with elevated privileges.

The following remediation steps are recommended / required by December 12, 2023: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Vulnerability Analysis

CVE-2023-4911 can be exploited with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.8 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

What is a Memory Corruption Vulnerability?

The software writes data past the end, or before the beginning, of the intended buffer. Typically, this can result in corruption of data, a crash, or code execution. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent write operation then produces undefined or unexpected results.

CVE-2023-4911 has been classified to as a Memory Corruption vulnerability or weakness.