CVE intelligence and bounded remediation
CVE-2018-3963 — An exploitable command injection vulnerability exists in the DHCP daemon configuration of the CUJO Smart Firewall
An exploitable command injection vulnerability exists in the DHCP daemon configuration of the CUJO Smart Firewall. When adding a new static DHCP address, its corresponding hostname is inserted into the dhcpd.conf file without prior sanitization, allowing for arbitrary execution of system commands. To trigger this vulnerability, an attacker can send a DHCP request message and set up the corresponding static DHCP entry.
- Severity
- Critical
- CVSS
- 9 (3.0)
- Published
- 2019-03-21
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-77
Affected products
- getcujo / smart_firewall / 7003
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
The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.