CVE intelligence and bounded remediation

CVE-2020-12242 — Valvesoftware Source security vulnerability

High CVSS 7.8

Valve Source allows local users to gain privileges by writing to the /tmp/hl2_relaunch file, which is later executed in the context of a different user account.

Severity
High
CVSS
7.8 (3.1)
Published
2020-04-27
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-78

Affected products

  • valvesoftware / source

Matched remediation archetype

Command, code, expression, and template injection

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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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