CVE-2020-28013 : Security Advisory and Response

Exim 4 before 4.94.2 allows Heap-based Buffer Overflow due to mishandling of specific command line input, potentially leading to privilege escalation from any user to root.

Understanding CVE-2020-28013

This CVE involves a vulnerability in Exim 4 versions prior to 4.94.2 that could be exploited for privilege escalation.

What is CVE-2020-28013?

Exim 4 before 4.94.2 is susceptible to a Heap-based Buffer Overflow triggered by incorrect handling of command line input, potentially enabling an attacker to elevate privileges from a regular user to root.

The Impact of CVE-2020-28013

The vulnerability could allow an unauthorized user to gain root privileges on the affected system, posing a significant security risk.

Technical Details of CVE-2020-28013

Examine the technical aspects of this CVE.

Vulnerability Description

The issue arises from Exim 4's improper processing of specific command line arguments, leading to a Heap-based Buffer Overflow that could be leveraged for privilege escalation.

Affected Systems and Versions

Product: Exim 4
Versions Affected: Versions prior to 4.94.2

Exploitation Mechanism

The vulnerability is exploited by manipulating the command line input, specifically mishandling the "-F '.('" parameter, which triggers the Heap-based Buffer Overflow.

Mitigation and Prevention

Learn how to address and prevent the CVE-2020-28013 vulnerability.

Immediate Steps to Take

Update Exim to version 4.94.2 or newer to mitigate the Heap-based Buffer Overflow.
Monitor system logs for any unusual activities that could indicate exploitation.

Long-Term Security Practices

Implement the principle of least privilege to restrict user access rights.
Regularly audit and review command line input handling mechanisms to identify and address potential vulnerabilities.

Patching and Updates

Stay informed about security updates for Exim and promptly apply patches to address known vulnerabilities.