CVE-2021-36191 Open redirect in Fortinet FortiWeb

What is CVE-2021-36191?

CVE-2021-36191 is a medium-severity vulnerability in Fortinet Fortiweb, published on 8 Dec 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

A url redirection to untrusted site ('open redirect') in Fortinet FortiWeb version 6.4.1 and below, 6.3.15 and below allows attacker to use the device as proxy via crafted GET parameters in requests to error handlers

Weakness: CWE-601

Which versions are affected by CVE-2021-36191?

It affects 1 product.

Products include Fortinet Fortiweb.

How do I fix CVE-2021-36191?

No fix has been published for CVE-2021-36191 yet. Limit exposure of the affected software until one is available.

Is CVE-2021-36191 being exploited?

There is no known exploitation of CVE-2021-36191 in the wild and no public exploit code.

Other vulnerabilities in Fortinet Fortiweb

• CVE-2025-25257 Fortinet FortiWeb SQL Injection Exploited Critical 9.6
• CVE-2025-64446 Fortinet FortiWeb Path Traversal Exploited Critical 9.4
• CVE-2025-58034 Fortinet FortiWeb OS Command Injection Exploited Medium 6.7
• CVE-2020-29015 SQL injection in Fortinet FortiWeb Critical 9.8
• CVE-2020-29016 Memory corruption in Fortinet FortiWeb Critical 9.8

All Fortinet Fortiweb vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-fpgv-9v95-hrgv.