CVE intelligence and bounded remediation

CVE-2020-36242 — Cryptography.Io Cryptography security vulnerability

Critical CVSS 9.1

In the cryptography package before 3.3.2 for Python, certain sequences of update calls to symmetrically encrypt multi-GB values could result in an integer overflow and buffer overflow, as demonstrated by the Fernet class.

Severity
Critical
CVSS
9.1 (3.1)
Published
2021-02-07
CISA KEV
Not currently listed
Ecosystem
python/pypi
Weaknesses
CWE-190, CWE-787

Affected products

  • cryptography.io / cryptography
  • fedoraproject / fedora / 33
  • oracle / communications_cloud_native_core_network_function_cloud_native_environment / 1.10.0

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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