CVE-2021-3444

 

Published at: - 23-03-2021 07:15

Last modified: - 26-10-2022 01:44

Total changes: - 10

Description

The bpf verifier in the Linux kernel did not properly handle mod32 destination register truncation when the source register was known to be 0. A local attacker with the ability to load bpf programs could use this gain out-of-bounds reads in kernel memory leading to information disclosure (kernel memory), and possibly out-of-bounds writes that could potentially lead to code execution. This issue was addressed in the upstream kernel in commit 9b00f1b78809 ("bpf: Fix truncation handling for mod32 dst reg wrt zero") and in Linux stable kernels 5.11.2, 5.10.19, and 5.4.101.

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

 

Verification logic

 

Reference

• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9b00f1b78809
• https://www.openwall.com/lists/oss-security/2021/03/23/2
• [oss-security] 20210323 [CVE-2021-3444] Linux kernel bpf verifier incorrect mod32 truncation-Mailing List, Third Party Advisory
• http://packetstormsecurity.com/files/162117/Kernel-Live-Patch-Security-Notice-LSN-0075-1.html
• https://security.netapp.com/advisory/ntap-20210416-0006/
• [debian-lts-announce] 20211015 [SECURITY] [DLA 2785-1] linux-4.19 security update-Mailing List, Third Party Advisory
• http://packetstormsecurity.com/files/164950/Kernel-Live-Patch-Security-Notice-LSN-0082-1.html

 

Keywords

NVD

 

CVE-2021-3444

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures