CVE-2021-26116 Explained : Impact and Mitigation

Fortinet FortiAuthenticator before version 6.3.1 is impacted by a vulnerability that allows an authenticated attacker to execute unauthorized commands. Here's what you need to know about CVE-2021-26116.

Understanding CVE-2021-26116

This section provides an overview of the vulnerability and its implications.

What is CVE-2021-26116?

The vulnerability in FortiAuthenticator before 6.3.1 arises from an improper neutralization of special elements used in an OS command. It enables an authenticated attacker to run unauthorized commands by providing specially crafted arguments.

The Impact of CVE-2021-20657

The impact of this vulnerability is rated as medium severity. It has a CVSS base score of 6.5 out of 10, with high impacts on confidentiality and integrity. Attackers with high privileges can exploit this issue, leading to the execution of unauthorized commands.

Technical Details of CVE-2021-26116

In this section, we delve into the technical aspects of the CVE-2021-26116 vulnerability.

Vulnerability Description

The vulnerability involves an OS command injection flaw in the command line interpreter of FortiAuthenticator. It allows authenticated attackers to execute malicious commands using specially crafted arguments.

Affected Systems and Versions

Fortinet FortiAuthenticator versions before 6.3.1 are affected by this vulnerability. Users operating on these versions are at risk of exploitation by malicious actors.

Exploitation Mechanism

Attackers can exploit this vulnerability by providing specially crafted arguments to existing commands on the FortiAuthenticator command line interpreter. This enables the execution of unauthorized commands under the attacker's control.

Mitigation and Prevention

To safeguard your systems from CVE-2021-26116, consider implementing the following mitigation strategies.

Immediate Steps to Take

Upgrade FortiAuthenticator to version 6.3.1 or later to eliminate the vulnerability.
Monitor network traffic and system logs for any unusual activities indicating exploitation.

Long-Term Security Practices

Conduct regular security audits and penetration testing to identify vulnerabilities proactively.
Educate users about safe computing practices and phishing awareness to prevent unauthorized access.

Patching and Updates

Stay abreast of security advisories from Fortinet and apply updates promptly to address security vulnerabilities.