CVE-2021-43206

MEDIUM

4.3

CVSS Score

Published: May 4, 2022 at 03:25 PM UTC

Updated: June 17, 2026 at 04:10 AM UTC

2 products affected across 1 vendorFortiOSFortiProxy

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Severity

MEDIUM4.3

Exploit prediction

EPSS 0.8%

SSVC

No known exploit

Description

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 requests triggering proxy-generated HTTP status codes pages.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

FortiOS · Fortinet

95%

5.6.0 ≤ v < 6.0.146.2.0 ≤ v < 6.2.106.4.0 ≤ v < 6.4.87.0.0 ≤ v < 7.0.4FortiOS 7.0.3, 7.0.2, 7.0.1, 7.0.0, 6.4.8, 6.4.7, 6.4.6, 6.4.5, 6.4.4, 6.4.3, 6.4.2, 6.4.1, 6.4.0, 6.2.10, 6.2.9, 6.2.8, 6.2.7, 6.2.6, 6.2.5, 6.2.4, 6.2.3, 6.2.2, 6.2.1, 6.2.0, 6.0.14, 6.0.13, 6.0.12, 6.0.11, 6.0.10, 6.0.9, 6.0.8, 6.0.7, 6.0.6, 6.0.5, 6.0.4, 6.0.3, 6.0.2, 6.0.1, 6.0.0, 5.6.14, 5.6.13, 5.6.12, 5.6.11, 5.6.10, 5.6.9, 5.6.8, 5.6.7, 5.6.6, 5.6.5, 5.6.4, 5.6.3, 5.6.2, 5.6.1, 5.6.0; FortiProxy 7.0.1, 7.0.0, 2.0.7, 2.0.6, 2.0.5, 2.0.4, 2.0.3, 2.0.2, 2.0.1, 2.0.0

Affected range stops below 6.0.14, so it looks safe — our inference, not a vendor statement

Affected range stops below 6.2.10, so it looks safe — our inference, not a vendor statement

Affected range stops below 6.4.8, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.0.4, so it looks safe — our inference, not a vendor statement

FortiProxy · Fortinet

95%

2.0.0 ≤ v < 2.0.97.0.0 ≤ v < 7.0.2FortiOS 7.0.3, 7.0.2, 7.0.1, 7.0.0, 6.4.8, 6.4.7, 6.4.6, 6.4.5, 6.4.4, 6.4.3, 6.4.2, 6.4.1, 6.4.0, 6.2.10, 6.2.9, 6.2.8, 6.2.7, 6.2.6, 6.2.5, 6.2.4, 6.2.3, 6.2.2, 6.2.1, 6.2.0, 6.0.14, 6.0.13, 6.0.12, 6.0.11, 6.0.10, 6.0.9, 6.0.8, 6.0.7, 6.0.6, 6.0.5, 6.0.4, 6.0.3, 6.0.2, 6.0.1, 6.0.0, 5.6.14, 5.6.13, 5.6.12, 5.6.11, 5.6.10, 5.6.9, 5.6.8, 5.6.7, 5.6.6, 5.6.5, 5.6.4, 5.6.3, 5.6.2, 5.6.1, 5.6.0; FortiProxy 7.0.1, 7.0.0, 2.0.7, 2.0.6, 2.0.5, 2.0.4, 2.0.3, 2.0.2, 2.0.1, 2.0.0

Affected range stops below 2.0.9, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.0.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://fortiguard.com/psirt/FG-IR-21-231

References (1)

x_refsource_CONFIRMVendor Advisory

Source: [email protected]

https://fortiguard.com/psirt/FG-IR-21-231

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.3MEDIUMfortinet

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: REQUIRED
Scope: UNCHANGED
Confidentiality: LOW
Integrity: NONE
Availability: NONE

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-209

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