CVE-2021-42075

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-11-08 · updated 2026-06-17
Weakness: CWE-772

Description

An issue was discovered in Barrier before 2.3.4. The barriers component (aka the server-side implementation of Barrier) does not correctly close file descriptors for established TCP connections. An unauthenticated remote attacker can thus cause file descriptor exhaustion in the server process, leading to denial of service.

Affected products

Barrier Project Barrier: before 2.3.4 — fixed in 2.3.4

How to fix

Upgrade to a fixed version: Barrier Project Barrier 2.3.4. Check the vendor advisory for mitigations.

References

http://www.openwall.com/lists/oss-security/2021/11/02/4
https://github.com/debauchee/barrier/releases/tag/v2.3.4
http://www.openwall.com/lists/oss-security/2021/11/02/4
https://github.com/debauchee/barrier/releases/tag/v2.3.4

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