CVE-2022-35843 : Security Advisory and Response

This article provides an in-depth analysis of CVE-2022-35843, a vulnerability in Fortinet's FortiOS and FortiProxy.

Understanding CVE-2022-35843

CVE-2022-35843 is an authentication bypass vulnerability in the SSH login component of FortiOS and FortiProxy, potentially allowing remote attackers to access devices.

What is CVE-2022-35843?

The vulnerability, categorized as an authentication bypass by assumed-immutable data issue (CWE-302), affects multiple versions of FortiOS and FortiProxy. Attackers can exploit the flaw by sending specially crafted responses from the Radius server.

The Impact of CVE-2022-35843

With a CVSS base score of 7.7, this high-severity vulnerability can result in unauthorized access, posing a significant risk to confidentiality, integrity, and availability of affected systems.

Technical Details of CVE-2022-35843

The following details shed light on the vulnerability's specifics:

Vulnerability Description

The flaw resides in the SSH login component of FortiOS and FortiProxy versions, enabling remote and unauthenticated attackers to bypass authentication mechanisms.

Affected Systems and Versions

FortiOS versions 7.2.0, 7.0.0 - 7.0.7, 6.4.0 - 6.4.9, 6.2, and 6.0 are impacted. FortiProxy versions 7.0.0 - 7.0.5, 2.0.0 - 2.0.10, and 1.2.0 are also vulnerable.

Exploitation Mechanism

Attackers leverage the vulnerability by manipulating Access-Challenge responses from the Radius server to gain unauthorized access to targeted devices.

Mitigation and Prevention

To mitigate the risks associated with CVE-2022-35843, users and organizations can take the following steps:

Immediate Steps to Take

Upgrade FortiOS to version 7.2.2 or above
Upgrade FortiOS to version 7.0.8 or above
Upgrade FortiOS to version 6.4.10 or above
Upgrade FortiProxy to version 7.0.7 or above
Upgrade FortiProxy to version 2.0.11 or above

Long-Term Security Practices

Implement strong access control mechanisms, regularly update software, and monitor for any unauthorized access attempts.

Patching and Updates

Stay informed about security patches and updates released by Fortinet to address vulnerabilities and enhance the security posture of your systems and devices.