Cyber Resilience

CVE-2021-42073

HighPublic PoC

Published: 08 November 2021

Published
08 November 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
EPSS Score 0.0061 70.2th percentile
Risk Priority 17 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-42073 is a high-severity Session Fixation (CWE-384) vulnerability in Barrier Project Barrier. Its CVSS base score is 8.2 (High).

Operationally, ranked in the top 29.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

An issue was discovered in Barrier before 2.4.0. An attacker can enter an active session state with the barriers component (aka the server-side implementation of Barrier) simply by supplying a client label that identifies a valid client configuration. This label…

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is "Unnamed" by default but could instead be guessed from hostnames or other publicly available information. In the active session state, an attacker can capture input device events from the server, and also modify the clipboard content on the server.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

barrier project
barrier
≤ 2.4.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-384

Session termination after a set interval shortens the usable lifetime of a fixed session identifier, making successful exploitation of session fixation more difficult.

addresses: CWE-384

Re-authentication typically forces issuance of a new session, limiting the window for exploitation of a previously fixed session identifier.

addresses: CWE-384

Enforces proper session ID generation and binding, preventing fixation of a known session token.

References