Cyber Resilience

CVE-2021-42761

Critical

Published: 16 February 2023

Published
16 February 2023
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 9.0 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0165 82.4th percentile
Risk Priority 19 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-42761 is a critical-severity Session Fixation (CWE-384) vulnerability in Fortinet Fortiweb. Its CVSS base score is 9.0 (Critical).

Operationally, ranked in the top 17.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

A condition for session fixation vulnerability [CWE-384] in the session management of FortiWeb versions 6.4 all versions, 6.3.0 through 6.3.16, 6.2.0 through 6.2.6, 6.1.0 through 6.1.2, 6.0.0 through 6.0.7, 5.9.0 through 5.9.1 may allow a remote, unauthenticated attacker to infer…

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the session identifier of other users and possibly usurp their session.

CWE(s)

Related Threats

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

Affected Assets

fortinet
fortiweb
5.6.0 — 5.9.2 · 6.0.0 — 6.0.8 · 6.1.0 — 6.1.3

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