CVE intelligence and bounded remediation

CVE-2021-3537 — Xmlsoft Libxml2 security vulnerability

Medium CVSS 5.9

A vulnerability found in libxml2 in versions before 2.9.11 shows that it did not propagate errors while parsing XML mixed content, causing a NULL dereference. If an untrusted XML document was parsed in recovery mode and post-validated, the flaw could be used to crash the application. The highest threat from this vulnerability is to system availability.

Severity
Medium
CVSS
5.9 (3.1)
Published
2021-05-14
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-476

Affected products

  • xmlsoft / libxml2
  • redhat / jboss_core_services
  • redhat / enterprise_linux / 6.0
  • redhat / enterprise_linux / 7.0
  • redhat / enterprise_linux / 8.0
  • debian / debian_linux / 9.0

Showing 6 representative product identities from 24 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
  • Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
  • Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.

Remediate safely

  • Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
  • Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
  • Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.

Authoritative sources

Complete CVE record and remediation plan

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