How severe is CVE-2021-28096?

CVE-2021-28096 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-2021-28096 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28096?

CVE-2021-28096 affects Stormshield Stormshield Network Security. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-28096?

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

When was CVE-2021-28096 published?

CVE-2021-28096 was published on 2022-01-27 and last updated on 2026-06-17.

CVE-2021-28096

CVE-2021-28096 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. The underlying weakness is classified as CWE-770.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 4.3
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Stormshield Stormshield Network Security
Published: 2022-01-27
Last modified: 2026-06-17

Description

An issue was discovered in Stormshield SNS before 4.2.3 (when the proxy is used). An attacker can saturate the proxy connection table. This would result in the proxy denying any new connections.

Frequently asked questions

What is CVE-2021-28096?: An issue was discovered in Stormshield SNS before 4.2.3 (when the proxy is used). An attacker can saturate the proxy connection table. This would result in the proxy denying any new connections.
How severe is CVE-2021-28096?: CVE-2021-28096 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-2021-28096 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28096?: CVE-2021-28096 affects Stormshield Stormshield Network Security. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-28096?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-28096 published?: CVE-2021-28096 was published on 2022-01-27 and last updated on 2026-06-17.

References

https://advisories.stormshield.eu/2021-005/

Affected products (1)

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

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