CVE-2023-50176 - Session Fixation Vulnerability in Fortinet FortiOS Allows Unauthorized Code Execution via Phishing SAML Authentication Link

A recently discovered vulnerability within Fortinet FortiOS, a popular network security operating system, allows attackers to execute unauthorized code or commands via phishing Secure Assertion Markup Language (SAML) authentication links. This vulnerability has been assigned the identifier CVE-2023-50176 by the Common Vulnerabilities and Exposures (CVE) project.

This blog post will highlight the severity of this vulnerability, discuss potential attack scenarios, and provide recommendations for mitigation.

Affected Software

Fortinet FortiOS versions 7.4. through 7.4.3, 7.2. through 7.2.7, and 7.. through 7..13 are impacted by this vulnerability.

Exploit Details

The session fixation vulnerability in Fortinet FortiOS enables an attacker to hijack a user's authenticated session by acquiring a valid session ID and then manipulating the victim into using it. This can be achieved through a phishing SAML authentication link, which appears legitimate but contains the malicious session ID.

Here's an example of a phishing SAML authentication link

https://auth.example.com/saml?SAMLRequest=<victim session token>

With a valid session token, the attacker can gain unauthorized access to the victim's session and execute code or commands.

Below is a code snippet demonstrating this vulnerability

import requests

# Attacker's session ID
attacker_session = "a1b2c3d4e5f6789"

# Phishing URL containing SAML authentication link with the attacker's session ID
phishing_url = "https://victim.example.com/login.php?session_id="; + attacker_session

# Send the phishing link to the victim via email or any other method
send_phishing_link(phishing_url)

# Use the attacker_session to access the victim's authenticated session
# and execute unauthorized code or commands

Original References

Fortinet acknowledges this vulnerability in their security advisory: FG-IR-21-228

The vulnerability has been assigned CVE-2023-50176 by the CVE project, and more information can be found here: CVE-2023-50176

Mitigation Recommendations

It is highly recommended to upgrade any affected Fortinet FortiOS instances to a non-vulnerable version as soon as possible. The following versions are not affected by this vulnerability:

FortiOS 7..14 or later

In addition to applying the appropriate software updates, it's critical to train and educate users in the organization about the risks of phishing attacks and how to recognize phishing attempts.

Conclusion

The session fixation vulnerability in Fortinet FortiOS (CVE-2023-50176) is a severe security issue that could allow an attacker to execute unauthorized code or commands via phishing SAML authentication links. Organizations using affected versions of Fortinet FortiOS should take immediate action to mitigate this vulnerability, including updating their software and educating their users about the dangers of phishing attacks.

Timeline

Published on: 11/12/2024 19:15:07 UTC
Last modified on: 12/12/2024 19:27:35 UTC