CVE-2021-36167 : Vulnerability Insights and Analysis

An improper authorization vulnerability in FortiClient Windows versions 7.0.0 and 6.4.6 and below, as well as 6.2.8 and below, may allow an unauthenticated attacker to bypass webfilter control by modifying the session-id parameter.

Understanding CVE-2021-36167

This CVE highlights an improper authorization vulnerability in FortiClient Windows that could enable an attacker to circumvent webfilter controls.

What is CVE-2021-36167?

The CVE-2021-36167 vulnerability concerns an improper authorization issue in specific versions of FortiClient Windows, potentially granting unauthorized access to bypass webfilter controls by tampering with the session-id parameter.

The Impact of CVE-2021-36167

With a CVSS base score of 4.1 (Medium severity), this vulnerability poses a risk for affected systems, allowing unauthenticated attackers to manipulate the session-id parameter and evade webfilter restrictions.

Technical Details of CVE-2021-36167

This section covers the intricate aspects of CVE-2021-36167.

Vulnerability Description

The vulnerability involves an improper authorization flaw in FortiClient Windows versions 7.0.0, 6.4.6, and below, as well as 6.2.8 and below, enabling unauthorized users to bypass webfilter controls.

Affected Systems and Versions

Fortinet's FortiClientWindows versions 7.0.0, 6.4.6, 6.4.5, 6.4.4, 6.4.3, 6.4.2, 6.4.1, 6.4.0, 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 are affected by this vulnerability.

Exploitation Mechanism

Attackers can exploit this vulnerability by leveraging an improper authorization issue in FortiClient Windows, allowing them to tamper with the session-id parameter and evade webfilter controls.

Mitigation and Prevention

Learn how to mitigate and prevent the risks associated with CVE-2021-36167.

Immediate Steps to Take

To address this vulnerability, users should apply security patches and updates provided by Fortinet promptly. Additionally, monitoring network activity for any suspicious behavior is crucial.

Long-Term Security Practices

Establishing strict access controls, regular security training for employees, and implementing intrusion detection systems can enhance long-term security against unauthorized access and malicious activities.

Patching and Updates

Regularly updating FortiClient Windows to the latest secure versions is essential to mitigate the risks posed by CVE-2021-36167.