CVE intelligence and bounded remediation

CVE-2020-11945 — An issue was discovered in Squid before 5.0.2

Critical CVSS 9.8

An issue was discovered in Squid before 5.0.2. A remote attacker can replay a sniffed Digest Authentication nonce to gain access to resources that are otherwise forbidden. This occurs because the attacker can overflow the nonce reference counter (a short integer). Remote code execution may occur if the pooled token credentials are freed (instead of replayed as valid credentials).

Severity
Critical
CVSS
9.8 (3.1)
Published
2020-04-23
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-190

Affected products

  • squid-cache / squid
  • debian / debian_linux / 9.0
  • debian / debian_linux / 10.0
  • opensuse / leap / 15.1
  • fedoraproject / fedora / 30
  • fedoraproject / fedora / 31

Showing 6 representative product identities from 13 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Command, code, expression, and template injection

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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