Is CVE-2018-4003 actively exploited?

No active exploitation of CVE-2018-4003 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2018-4003 be exploited remotely?

Yes. CVE-2018-4003 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2018-4003?

CVE-2018-4003 has a CVSS score of 9.8 (CRITICAL).

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CRITICAL

CVE-2018-4003

CWE-787Published: March 21, 2019· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

An exploitable heap overflow vulnerability exists in the mdnscap binary of the CUJO Smart Firewall running firmware 7003. The string lengths are handled incorrectly when parsing character strings in mDNS resource records, leading to arbitrary code execution in the context of the mdnscap process. An unauthenticated attacker can send an mDNS message to trigger this vulnerability.

NVD Source

Technical Analysis

CVE-2018-4003 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.