How severe is CVE-2021-3384?

CVE-2021-3384 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2021-3384 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3384?

CVE-2021-3384 affects Stormshield Stormshield Network Security. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-3384?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-3384 published?

CVE-2021-3384 was published on 2021-03-02 and last updated on 2026-06-17.

CVE-2021-3384

CVE-2021-3384 is a medium-severity vulnerability in Stormshield Stormshield Network Security with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 1% (59th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Stormshield Stormshield Network Security
Published: 2021-03-02
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-3384?: 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.
How severe is CVE-2021-3384?: CVE-2021-3384 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2021-3384 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3384?: CVE-2021-3384 affects Stormshield Stormshield Network Security. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-3384?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-3384 published?: CVE-2021-3384 was published on 2021-03-02 and last updated on 2026-06-17.

References

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

Affected products (1)

cpe:2.3:a:stormshield:stormshield_network_security:*:*:*:*:*:*:*:*

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