CVE intelligence and bounded remediation

CVE-2020-9866 — A buffer overflow was addressed with improved bounds checking

Critical CVSS 9.8

A buffer overflow was addressed with improved bounds checking. This issue is fixed in macOS Catalina 10.15.6, Security Update 2020-004 Mojave, Security Update 2020-004 High Sierra. A buffer overflow may result in arbitrary code execution.

Severity
Critical
CVSS
9.8 (3.1)
Published
2020-10-27
CISA KEV
Not currently listed
Ecosystem
apple/platform
Weaknesses
CWE-120

Affected products

  • apple / mac_os_x

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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