CVE-2020-28026 Explained : Impact and Mitigation

Exim 4 before 4.94.2 is susceptible to an Improper Neutralization of Line Delimiters vulnerability, particularly in non-default configurations enabling Delivery Status Notification (DSN). This flaw could allow unauthenticated remote attackers to execute arbitrary commands as root.

Understanding CVE-2020-28026

Exim 4 before 4.94.2 vulnerability with potential severe consequences.

What is CVE-2020-28026?

Exim 4 before 4.94.2 is affected by an improper neutralization of line delimiters vulnerability, which could be exploited by unauthenticated remote attackers to execute arbitrary commands as root.

The Impact of CVE-2020-28026

The vulnerability in Exim 4 before 4.94.2 could lead to unauthenticated remote attackers executing arbitrary commands with root privileges.

Technical Details of CVE-2020-28026

Exim 4 before 4.94.2 vulnerability details.

Vulnerability Description

Certain uses of ORCPT= can introduce a newline into a spool header file, enabling unauthenticated remote attackers to execute arbitrary commands as root.

Affected Systems and Versions

Product: Exim 4
Vendor: N/A
Versions: N/A

Exploitation Mechanism

The vulnerability arises in non-default configurations that allow Delivery Status Notification (DSN), enabling attackers to inject commands.

Mitigation and Prevention

Protect systems from CVE-2020-28026.

Immediate Steps to Take

Update Exim to version 4.94.2 or later.
Disable DSN if not required.
Monitor for any unauthorized access or suspicious activities.

Long-Term Security Practices

Regularly update and patch Exim and other software.
Implement strong access controls and authentication mechanisms.
Conduct security audits and penetration testing periodically.
Stay informed about security vulnerabilities and best practices.

Patching and Updates

Ensure timely installation of security patches and updates to mitigate the CVE-2020-28026 vulnerability.