CVE intelligence and bounded remediation

CVE-2021-42716 — An issue was discovered in stb stb_image.h 2.27

High CVSS 7.1

An issue was discovered in stb stb_image.h 2.27. The PNM loader incorrectly interpreted 16-bit PGM files as 8-bit when converting to RGBA, leading to a buffer overflow when later reinterpreting the result as a 16-bit buffer. An attacker could potentially have crashed a service using stb_image, or read up to 1024 bytes of non-consecutive heap data without control over the read location.

Severity
High
CVSS
7.1 (3.1)
Published
2021-10-21
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-120

Affected products

  • nothings / stb_image.h / 2.27
  • fedoraproject / fedora / 33
  • fedoraproject / fedora / 34
  • fedoraproject / fedora / 35

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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