CVE intelligence and bounded remediation

CVE-2021-33440 — An issue was discovered in mjs (mJS: Restricted JavaScript engine), ES6 (JavaScript version 6)

Medium CVSS 5.5

An issue was discovered in mjs (mJS: Restricted JavaScript engine), ES6 (JavaScript version 6). There is NULL pointer dereference in mjs_bcode_commit() in mjs.c.

Severity
Medium
CVSS
5.5 (3.1)
Published
2022-07-26
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-476

Affected products

  • cesanta / mjs

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

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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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