Cyber Resilience

CVE-2021-43206

Medium

Published: 04 May 2022

Published
04 May 2022
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS Score 0.0039 60.5th percentile
Risk Priority 9 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-43206 is a medium-severity Generation of Error Message Containing Sensitive Information (CWE-209) vulnerability in Fortinet Fortios. Its CVSS base score is 4.3 (Medium).

Operationally, ranked in the top 39.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

A server-generated error message containing sensitive information in Fortinet FortiOS 7.0.0 through 7.0.3, 6.4.0 through 6.4.8, 6.2.x, 6.0.x and FortiProxy 7.0.0 through 7.0.1, 2.0.x allows malicious webservers to retrieve a web proxy's client username and IP via same origin HTTP…

more

requests triggering proxy-generated HTTP status codes pages.

CWE(s)

Related Threats

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

Affected Assets

fortinet
fortiproxy
2.0.0 — 2.0.9 · 7.0.0 — 7.0.2
fortinet
fortios
5.6.0 — 6.0.14 · 6.2.0 — 6.2.10 · 6.4.0 — 6.4.8

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-209

Detects error messages that leak sensitive information as evidence of disclosure.

addresses: CWE-209

The control directly mitigates generation of error messages containing sensitive authentication details by requiring obscured feedback instead of verbose responses.

addresses: CWE-209

Misdirection allows generation of misleading error messages that withhold or falsify sensitive details.

addresses: CWE-209

Explicitly requires error messages to avoid including sensitive or exploitable details while still supporting corrective action.

addresses: CWE-209

Validation ensures error messages contain only expected, non-sensitive content and blocks leakage via verbose errors.

addresses: CWE-209

Fail-safe procedures can be defined to suppress or sanitize error output, reducing generation of messages that contain sensitive information.

References