CVE-2021-33576 Explained : Impact and Mitigation

A path traversal vulnerability was found in Cleo LexiCom version 5.5.0.0 that allows an attacker to write files to arbitrary locations on the disk.

Understanding CVE-2021-33576

This CVE describes a security issue in Cleo LexiCom that can be exploited by manipulating the filename in the AS2 message.

What is CVE-2021-33576?

CVE-2021-33576 is a path traversal vulnerability in Cleo LexiCom 5.5.0.0. Attackers can specify a malicious filename with path-traversal characters, enabling them to write files to unauthorized locations on the disk.

The Impact of CVE-2021-33576

This vulnerability can lead to unauthorized file writes, potentially allowing attackers to overwrite critical system files or plant malicious scripts on the server.

Technical Details of CVE-2021-33576

This section provides more detailed information about the vulnerability.

Vulnerability Description

The vulnerability arises from improper handling of filenames within AS2 messages in Cleo LexiCom, which can be abused to perform path traversal attacks.

Affected Systems and Versions

Cleo LexiCom version 5.5.0.0 is affected by this vulnerability.

Exploitation Mechanism

Attackers can exploit this issue by inserting path-traversal characters in the filename field of AS2 messages, allowing them to write files to unintended locations.

Mitigation and Prevention

To secure systems from CVE-2021-33576, consider the following mitigation strategies.

Immediate Steps to Take

Update Cleo LexiCom to the latest version to patch the vulnerability.
Restrict access to the AS2 message functionality to trusted entities only.

Long-Term Security Practices

Regularly monitor and audit file write activities on the server.
Implement input validation mechanisms to sanitize user-controlled input.

Patching and Updates

Stay informed about security updates from Cleo and apply patches promptly to address known vulnerabilities.