CVE intelligence and bounded remediation
CVE-2021-39173 — Cachet is an open source status page system
Cachet is an open source status page system. Prior to version 2.5.1 authenticated users, regardless of their privileges (User or Admin), can trick Cachet and install the instance again, leading to arbitrary code execution on the server. This issue was addressed in version 2.5.1 by improving the middleware `ReadyForUse`, which now performs a stricter validation of the instance name. As a workaround, only allow trusted source IP addresses to access to the administration dashboard.
- Severity
- High
- CVSS
- 8.8 (3.1)
- Published
- 2021-08-27
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-704
Affected products
- catchethq / catchet
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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