SB2021070721 - Privilege escalation in Linux kernel



SB2021070721 - Privilege escalation in Linux kernel

Published: July 7, 2021 Updated: August 13, 2022

Security Bulletin ID SB2021070721
Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Code execution

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Improper Verification of Cryptographic Signature (CVE-ID: CVE-2021-35039)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to improper signature handling in the kernel/module.c in Linux kernel. If the kernel module is not signed, it still can be loaded into the system via init_module if module.sig_enforce=1 command-line argument is used. As a result, a local user can load unsigned and potentially malicious kernel modules.


Remediation

Install update from vendor's website.