CVE-2021-43057
CWE-416Published: October 28, 2021· Updated: Jun 17, 2026
Official Description
An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in selinux_ptrace_traceme (aka the SELinux handler for PTRACE_TRACEME) could be used by local attackers to cause memory corruption and escalate privileges, aka CID-a3727a8bac0a. This occurs because of an attempt to access the subjective credentials of another task.
Technical Analysis
CVE-2021-43057 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.8.
From a weakness classification perspective (CWE-416): Use-after-free vulnerabilities involve accessing memory after it has been freed, often enabling arbitrary code execution.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (8)
Quick Facts
Related CVEs (CWE-416)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-43057 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts