CVE intelligence and bounded remediation

CVE-2021-29968 — When drawing text onto a canvas with WebRender disabled, an out of bounds read could occur

High CVSS 8.1

When drawing text onto a canvas with WebRender disabled, an out of bounds read could occur. *This bug only affects Firefox on Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 89.0.1.

Severity
High
CVSS
8.1 (3.1)
Published
2021-06-24
CISA KEV
Not currently listed
Ecosystem
browser
Weaknesses
CWE-125

Affected products

  • mozilla / firefox

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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