#VU62772 Information disclosure in FortiOS - CVE-2021-43206

Vulnerability identifier: #VU62772

Vulnerability risk: Medium

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-43206

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
FortiOS
Operating systems & Components / Operating system

Vendor: Fortinet, Inc

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to excessive data output in server-generated error messages. A remote attacker can trick the victim to connect to a malicious webserver and retrieve a web proxy's client username and IP via same origin HTTP requests triggering proxy-generated HTTP status codes pages.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

FortiOS: 6.0.0 - 6.0.14, 6.2.0 - 6.2.10, 6.4.0 - 6.4.8, 7.0.0 - 7.0.3

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

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.