CVE-2021-43057: linux linux_kernel Use After Free
Vulnerability summary
CVE-2021-43057 is a high (CVSS 7.8) Use After Free vulnerability in linux linux_kernel. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 40.8% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 28-10-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.49%
Chance of exploitation in the next 30 days
Percentile
41%
Versus all other CVEs
30-day change
0.00 pp
From 0.49% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundExploit Reference (bugs.chromium.org)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Ubuntu25 products
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.3All versions (No fix recorded)
- linux-aws-5.8All versions (No fix recorded)
- linux-azureAll versions (No fix recorded)
- linux-azure-5.3All versions (No fix recorded)
Debian1 product
- linux< 5.14.9-1
Linux1 product
- linux_kernel≥ 5.13, < 5.14.8
4 vendors · 35 products
References
10 links- bugs.chromium.org/p/project-zero/issues/detail?id=2229X Refsource MISCREPORTExploitPatchThird Party Advisory
- cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.14.8X Refsource MISCREPORTPatchRelease NotesVendor Advisory
