CVE intelligence and bounded remediation

CVE-2021-32921 — An issue was discovered in Prosody before 0.11.9

Medium CVSS 5.9

An issue was discovered in Prosody before 0.11.9. It does not use a constant-time algorithm for comparing certain secret strings when running under Lua 5.2 or later. This can potentially be used in a timing attack to reveal the contents of secret strings to an attacker.

Severity
Medium
CVSS
5.9 (3.1)
Published
2021-05-13
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-362

Affected products

  • prosody / prosody
  • fedoraproject / fedora / 32
  • fedoraproject / fedora / 33
  • fedoraproject / fedora / 34
  • debian / debian_linux / 9.0

Matched remediation archetype

Race condition, TOCTOU, and lifecycle synchronization

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Check exposure

  • Map concurrent actors, shared state, lock boundaries, signals, callbacks, retries, and check-then-use sequences in the affected path.
  • Determine whether untrusted users can influence timing, object names, filesystem state, or repeated state transitions.
  • Identify clustered and multi-process behavior that repository-local tests may not represent.

Remediate safely

  • Make the sensitive state transition atomic or protect it with a consistently ordered synchronization primitive.
  • Perform authorization and invariant checks on the same authoritative object and transaction used for the operation.
  • Use unique private resources, safe ownership transfer, and idempotent operations; add deterministic concurrency regression tests.

Authoritative sources

Complete CVE record and remediation plan

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