CVE-2020-5239 : Exploit Details and Defense Strategies

In Mailu before version 1.7, an authenticated user can exploit a vulnerability in Mailu fetchmail script and gain full access to a Mailu instance. This CVE has a CVSS base score of 8.7, indicating a high severity level.

Understanding CVE-2020-5239

This CVE pertains to an unspecified vulnerability in the fetchmail script in Mailu.

What is CVE-2020-5239?

CVE-2020-5239 is a security vulnerability in Mailu versions prior to 1.7 that allows an authenticated user to exploit the fetchmail script, potentially leading to unauthorized access to the Mailu instance.

The Impact of CVE-2020-5239

The impact of this vulnerability is rated as high, with confidentiality, integrity, and privileges being compromised. Mailu servers with open registration or untrusted users are particularly at risk.

Technical Details of CVE-2020-5239

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability in the fetchmail script in Mailu versions before 1.7 allows authenticated users to gain unauthorized access to Mailu instances.

Affected Systems and Versions

Product: Mailu
Vendor: Mailu
Versions Affected: < 1.7

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Network
Privileges Required: Low
User Interaction: Required
Scope: Changed
Confidentiality Impact: High
Integrity Impact: High
Availability Impact: None

Mitigation and Prevention

Protect your systems from CVE-2020-5239 by following these mitigation strategies.

Immediate Steps to Take

Upgrade Mailu to version 1.7 or higher to patch the vulnerability.
Restrict access to Mailu servers to trusted users only.
Monitor server logs for any suspicious activities.

Long-Term Security Practices

Regularly update and patch Mailu and other software components.
Implement strong authentication mechanisms and access controls.
Conduct security audits and penetration testing periodically.

Patching and Updates

Patch the vulnerability by updating to Mailu version 1.7 or later.
Follow detailed instructions provided by Mailu on securing the server after patching.