CVE-2021-3516: debian debian_linux Use After Free

Vulnerability summary

CVE-2021-3516 is a high (CVSS 7.8) Use After Free vulnerability in debian debian_linux. EPSS estimates a 2.04% chance of exploitation in the next 30 days, higher than 81.1% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 01-06-2021
   PublishedVulnerability first disclosed.
2. 14-10-2026
   Last modifiedVulnerability information updated.

Description

There's a flaw in libxml2's xmllint in versions before 2.9.11. An attacker who is able to submit a crafted file to be processed by xmllint could trigger a use-after-free. The greatest impact of this flaw is to confidentiality, integrity, and availability.

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.