How severe is CVE-2021-42074?

CVE-2021-42074 has a CVSS 3.x base score of 7.5, rated high 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 high.

Is CVE-2021-42074 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42074?

CVE-2021-42074 affects Barrier Project Barrier. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42074?

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

When was CVE-2021-42074 published?

CVE-2021-42074 was published on 2021-11-08 and last updated on 2026-06-17.

CVE-2021-42074

CVE-2021-42074 is a high-severity vulnerability in Barrier Project Barrier with a CVSS 3.x base score of 7.5. 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-416.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-416
Affected product: Barrier Project Barrier
Published: 2021-11-08
Last modified: 2026-06-17

Description

An issue was discovered in Barrier before 2.3.4. An unauthenticated attacker can cause a segmentation fault in the barriers component (aka the server-side implementation of Barrier) by quickly opening and closing TCP connections while sending a Hello message for each TCP session.

Frequently asked questions

What is CVE-2021-42074?: An issue was discovered in Barrier before 2.3.4. An unauthenticated attacker can cause a segmentation fault in the barriers component (aka the server-side implementation of Barrier) by quickly opening and closing TCP connections while sending a Hello message for each TCP session.
How severe is CVE-2021-42074?: CVE-2021-42074 has a CVSS 3.x base score of 7.5, rated high 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 high.
Is CVE-2021-42074 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42074?: CVE-2021-42074 affects Barrier Project Barrier. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42074?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-42074 published?: CVE-2021-42074 was published on 2021-11-08 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:barrier_project:barrier:*:*:*:*:*:*:*:*

More vulnerabilities in Barrier Project Barrier

CVE-2021-42072 — High (CVSS 8.8): An issue was discovered in Barrier before 2.4.0. The barriers component (aka the server-side implementation of Barrier)…
CVE-2021-42073 — High (CVSS 8.2): An issue was discovered in Barrier before 2.4.0. An attacker can enter an active session state with the barriers…
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