How severe is CVE-2021-37592?

CVE-2021-37592 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-37592 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-37592?

CVE-2021-37592 affects Oisf Suricata. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-37592?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-37592 published?

CVE-2021-37592 was published on 2021-11-19 and last updated on 2026-06-17.

CVE-2021-37592

CVE-2021-37592 is a critical-severity vulnerability in Oisf Suricata with a CVSS 3.x base score of 9.8. 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-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Oisf Suricata
Published: 2021-11-19
Last modified: 2026-06-17

Description

Suricata before 5.0.8 and 6.x before 6.0.4 allows TCP evasion via a client with a crafted TCP/IP stack that can send a certain sequence of segments.

Frequently asked questions

What is CVE-2021-37592?: Suricata before 5.0.8 and 6.x before 6.0.4 allows TCP evasion via a client with a crafted TCP/IP stack that can send a certain sequence of segments.
How severe is CVE-2021-37592?: CVE-2021-37592 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-37592 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-37592?: CVE-2021-37592 affects Oisf Suricata. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-37592?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-37592 published?: CVE-2021-37592 was published on 2021-11-19 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:oisf:suricata:*:*:*:*:*:*:*:*

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