PatchTheCVECVE-2018-4002: An exploitable denial-of-service vulnerability exists in the mdnscap binary of the CUJO Smart Firewall running
CVE-2018-4002 is a high-severity flaw (CVSS 7.5) affecting smart firewall firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
An exploitable denial-of-service vulnerability exists in the mdnscap binary of the CUJO Smart Firewall running firmware 7003. When parsing labels in mDNS packets, the firewall unsafely handles label compression pointers, leading to an uncontrolled recursion that eventually exhausts the stack, crashing the mdnscap process. An unauthenticated attacker can send an mDNS message to trigger this vulnerability.
Why this priority
- High severity
- Public exploit reference
- Remotely exploitable, no login, no user action
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 7.5 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.6% (top 25%) |
| CISA exploited list | No |
| Weakness | CWE-674 |
| Published | 2019-10-31 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2018-4002?
smart firewall firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2018-4002 being exploited?
CVE-2018-4002 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2018-4002 affect?
CVE-2018-4002 affects smart firewall firmware. Severity is high (CVSS 7.5). An exploitable denial-of-service vulnerability exists in the mdnscap binary of the CUJO Smart Firewall running firmware 7003. When parsing labels in mDNS packets, the firewall unsafely handles label compression pointers, leading to an uncon
How urgent is CVE-2018-4002?
Priority 55/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action