CVE-2020-28017 : Vulnerability Insights and Analysis

Exim 4 before 4.94.2 allows Integer Overflow to Buffer Overflow in receive_add_recipient via an e-mail message with fifty million recipients. Remote exploitation may be challenging due to resource consumption.

Understanding CVE-2020-28017

Exim vulnerability allowing an Integer Overflow to Buffer Overflow in a specific scenario.

What is CVE-2020-28017?

Exim 4 before 4.94.2 is susceptible to an Integer Overflow leading to a Buffer Overflow when processing emails with an excessive number of recipients.

The Impact of CVE-2020-28017

Successful exploitation could result in a Buffer Overflow, potentially leading to arbitrary code execution or denial of service.
Remote exploitation may be hindered by the significant resource consumption required.

Technical Details of CVE-2020-28017

Examination of the technical aspects of the vulnerability.

Vulnerability Description

Exim 4 before 4.94.2 is vulnerable to an Integer Overflow that can trigger a Buffer Overflow in the receive_add_recipient function.

Affected Systems and Versions

Exim version 4 before 4.94.2 is affected.

Exploitation Mechanism

Exploitation involves sending an email with an excessive number of recipients, causing the Integer Overflow to lead to a Buffer Overflow.

Mitigation and Prevention

Measures to address and prevent the CVE-2020-28017 vulnerability.

Immediate Steps to Take

Update Exim to version 4.94.2 or later to mitigate the vulnerability.
Monitor system resources for unusual email processing behavior.

Long-Term Security Practices

Regularly update and patch Exim to the latest versions to prevent known vulnerabilities.

Patching and Updates

Stay informed about security advisories and promptly apply patches to secure the Exim mail server.