CVE-2020-28012 : Vulnerability Insights and Analysis

Exim 4 before 4.94.2 allows Exposure of File Descriptor to Unintended Control Sphere due to a privileged pipe lacking a close-on-exec flag.

Understanding CVE-2020-28012

Exim vulnerability exposing file descriptors to unintended control.

What is CVE-2020-28012?

Exim 4 before version 4.94.2 is vulnerable to exposing file descriptors to unintended control due to a privileged pipe lacking a close-on-exec flag.

The Impact of CVE-2020-28012

This vulnerability could allow attackers to gain unauthorized access and potentially manipulate file descriptors, leading to unauthorized control over the affected system.

Technical Details of CVE-2020-28012

Examination of the technical aspects of the CVE.

Vulnerability Description

The issue arises from the use of a privileged pipe in Exim's rda_interpret without the necessary close-on-exec flag, enabling exposure of file descriptors to unintended control.

Affected Systems and Versions

Product: Exim 4
Versions affected: Before 4.94.2

Exploitation Mechanism

Attackers can exploit this vulnerability to gain unauthorized access and manipulate file descriptors by leveraging the lack of a close-on-exec flag in the privileged pipe.

Mitigation and Prevention

Measures to address and prevent the CVE-2020-28012 vulnerability.

Immediate Steps to Take

Update Exim to version 4.94.2 or newer to mitigate the vulnerability.
Monitor system logs for any suspicious activities that may indicate exploitation attempts.

Long-Term Security Practices

Regularly update and patch Exim and other software to prevent known vulnerabilities.
Implement access controls and least privilege principles to limit potential attack surfaces.

Patching and Updates

Apply security patches promptly to ensure that known vulnerabilities are addressed and system security is maintained.