Use After Free in Linux Kernel

CVE-2021-33033

The Linux kernel before 5.11.14 has a use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO refcounting for the DOI definitions is mishandled, aka CID-ad5d07f4a9cd. This leads to writing an arbitrary value.

Vulnerability class: Use-After-Free

EPSS: 0.006 (44.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

  • cve@mitre.org (Patch, Mailing List, x_refsource_MISC, Vendor Advisory)
  • cve@mitre.org (Exploit, Mailing List, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Patch, Mailing List, x_refsource_MISC, Vendor Advisory)
  • cve@mitre.org (Patch, Mailing List, x_refsource_MISC, Vendor Advisory)
  • cve@mitre.org (Patch, Mailing List, x_refsource_MISC, Vendor Advisory)

Frequently asked questions

What is CVE-2021-33033?
CVE-2021-33033 is a high-severity vulnerability in Linux Kernel, classified under Use After Free. CVSS score: 7.8/10. Published 2021-05-14.
How severe is CVE-2021-33033?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2021-33033 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.