SB2021070721 - Privilege escalation in Linux kernel

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Main Vulnerability Database SB2021070721

SB2021070721 - Privilege escalation in Linux kernel

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

Security Bulletin ID SB2021070721
CSH 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 vulnerability.


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

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]


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.

References