CVE-2021-3384

Name: CVE-2021-3384
Creator: NVD / NIST
Published: 2021-03-02T18:15:15.977+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 1.02%

Last modified Jun 17, 2026

CVE-2021-3384 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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. EPSS estimates a 1.02% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS Probability

1.02%

58.9th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Stormshield	Stormshield Network Security	>= 2.0.0, < 2.7.8
Stormshield	Stormshield Network Security	>= 2.8.0, <= 2.16.0
Stormshield	Stormshield Network Security	>= 3.0.0, <= 3.7.17
Stormshield	Stormshield Network Security	>= 3.8.0, <= 3.11.5
Stormshield	Stormshield Network Security	>= 4.0.0, < 4.1.5

References

https://advisories.stormshield.eu/2020-049/Vendor Advisory
https://advisories.stormshield.eu/2020-049/Vendor Advisory

Timeline

Published: Mar 2, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3384?

How severe is CVE-2021-3384?

CVE-2021-3384 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 1.02% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3384?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-3384?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST