CVE intelligence and bounded remediation
CVE-2018-17208 — Linksys Velop Firmware security vulnerability
Linksys Velop 1.1.2.187020 devices allow unauthenticated command injection, providing an attacker with full root access, via cgi-bin/zbtest.cgi or cgi-bin/zbtest2.cgi (scripts that can be discovered with binwalk on the firmware, but are not visible in the web interface). This occurs because shell metacharacters in the query string are mishandled by ShellExecute, as demonstrated by the zbtest.cgi?cmd=level&level= substring. This can also be exploited via CSRF.
- Severity
- High
- CVSS
- 9.3 (2.0)
- Published
- 2018-09-19
- CISA KEV
- Not currently listed
- Ecosystem
- operating-system
- Weaknesses
- CWE-78
Affected products
- linksys / velop_firmware / 1.1.2.187020
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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