CVE-2020-28011 Explained : Impact and Mitigation

Exim 4 before 4.94.2 allows Heap-based Buffer Overflow in queue_run via two sender options: -R and -S. This may cause privilege escalation from exim to root.

Understanding CVE-2020-28011

Exim vulnerability allowing Heap-based Buffer Overflow leading to privilege escalation.

What is CVE-2020-28011?

CVE-2020-28011 is a vulnerability in Exim 4 before version 4.94.2 that enables a Heap-based Buffer Overflow through specific sender options.

The Impact of CVE-2020-28011

The vulnerability can be exploited to achieve privilege escalation from the Exim mail server to root level, potentially leading to unauthorized access and control.

Technical Details of CVE-2020-28011

Examination of the technical aspects of the vulnerability.

Vulnerability Description

The vulnerability in Exim 4 allows a Heap-based Buffer Overflow in the queue_run function when using the -R and -S sender options.

Affected Systems and Versions

Affected System: Exim 4 versions before 4.94.2
Affected Component: queue_run function

Exploitation Mechanism

The vulnerability can be exploited by crafting malicious input to trigger the Heap-based Buffer Overflow, potentially leading to privilege escalation.

Mitigation and Prevention

Measures to mitigate the impact of CVE-2020-28011.

Immediate Steps to Take

Update Exim to version 4.94.2 or later to patch the vulnerability
Monitor for any unauthorized access or unusual activities on the Exim mail server

Long-Term Security Practices

Regularly update and patch all software components to prevent known vulnerabilities
Implement network segmentation and access controls to limit the impact of potential breaches

Patching and Updates

Apply security patches promptly to ensure the Exim server is protected against known vulnerabilities