CVE intelligence and bounded remediation

CVE-2018-20122 — Fastweb Fastgate Firmware security vulnerability

Critical CVSS 9.8

The web interface on FASTGate Fastweb devices with firmware through 0.00.47_FW_200_Askey 2017-05-17 (software through 1.0.1b) exposed a CGI binary that is vulnerable to a command injection vulnerability that can be exploited to achieve remote code execution with root privileges. No authentication is required in order to trigger the vulnerability.

Severity
Critical
CVSS
9.8 (3.0)
Published
2019-02-21
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-78

Affected products

  • fastweb / fastgate_firmware

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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