Is CVE-2021-3384 actively exploited?

No active exploitation of CVE-2021-3384 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-3384 be exploited remotely?

Yes. CVE-2021-3384 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-3384?

CVE-2021-3384 has a CVSS score of 5.3 (MEDIUM).

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MEDIUM

CVE-2021-3384

NVD-CWE-noinfoPublished: March 2, 2021· Updated: Jun 17, 2026

5.3

CVSS v3.1

Official Description

A vulnerability in Stormshield Network Security could allow an attacker to trigger a protection related to ARP/NDP tables management, which would temporarily prevent the system to contact new hosts via IPv4 or IPv6. This affects versions 2.0.0 to 2.7.7, 2.8.0 to 2.16.0, 3.0.0 to 3.7.16, 3.8.0 to 3.11.4, and 4.0.0 to 4.1.5. Fixed in versions 2.7.8, 3.7.17, 3.11.5, and 4.2.0.

NVD Source

Technical Analysis

CVE-2021-3384 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.