CVE-2021-42753 : Security Advisory and Response

A vulnerability in FortiWeb management interface could allow an attacker to delete files and directories on the device.

Understanding CVE-2021-42753

This CVE involves a path traversal vulnerability in specific versions of FortiWeb, potentially leading to unauthorized file and directory deletions.

What is CVE-2021-42753?

This vulnerability in FortiWeb management interface versions 6.4.1 and below, along with several other versions, enables authenticated attackers to delete files and directories on the device.

The Impact of CVE-2021-42753

The impact of this vulnerability is considered high, with a base score of 8.1. An attacker exploiting this flaw can cause significant availability and integrity issues on the affected device.

Technical Details of CVE-2021-42753

This section covers specific technical details of the CVE.

Vulnerability Description

The vulnerability arises from an improper limitation of a pathname, allowing attackers to perform path traversal and delete files and directories on the device.

Affected Systems and Versions

The affected versions include FortiWeb management interface 6.4.1 and below, as well as versions 6.3.15, 6.2.x, 6.1.x, 6.0.x, 5.9.x, and 5.8.x.

Exploitation Mechanism

Attackers need to be authenticated to exploit this vulnerability, abusing the path traversal weakness to delete arbitrary files and directories.

Mitigation and Prevention

Protective measures against CVE-2021-42753.

Immediate Steps to Take

Apply relevant patches and updates provided by the vendor.
Monitor system logs for any suspicious activities related to file deletions.

Long-Term Security Practices

Implement the principle of least privilege to limit user capabilities.
Regularly conduct security audits and penetration testing to identify vulnerabilities.

Patching and Updates

Ensure that systems are regularly updated with the latest security patches from the vendor.