CVE-2017-7692 : Vulnerability Insights and Analysis

A vulnerability has been found in versions of SquirrelMail prior to 1.4.22 that allows for remote code execution after authentication. The issue arises from mishandling of a sendmail.cf file in a popen call.

Understanding CVE-2017-7692

SquirrelMail 1.4.22 (and versions before 20170427_0200-SVN) is susceptible to post-authentication remote code execution via a mishandled sendmail.cf file.

What is CVE-2017-7692?

The vulnerability in SquirrelMail allows attackers to execute arbitrary shell commands on the server by manipulating the sendmail command line.

The Impact of CVE-2017-7692

Exploitation of this vulnerability can lead to the execution of arbitrary shell commands on the server, posing a significant security risk.

Technical Details of CVE-2017-7692

SquirrelMail's vulnerability can be further understood through technical details.

Vulnerability Description

The issue lies in the Deliver_SendMail.class.php file, specifically within the initStream function's usage of escapeshellcmd() to sanitize the sendmail command prior to execution. The incorrect use of escapeshellcmd() allows for injection of arbitrary command parameters.

Affected Systems and Versions

Versions of SquirrelMail prior to 1.4.22 (before 20170427_0200-SVN)

Exploitation Mechanism

Attackers can upload a sendmail.cf file as an email attachment and inject the sendmail.cf filename with the -C option within the "Options > Personal Informations > Email Address" setting to trigger arbitrary command execution.

Mitigation and Prevention

Protecting systems from CVE-2017-7692 requires immediate steps and long-term security practices.

Immediate Steps to Take

Update SquirrelMail to version 1.4.22 or later to mitigate the vulnerability.
Monitor system logs for any suspicious activities.

Long-Term Security Practices

Regularly update software and apply security patches promptly.
Implement strong email attachment scanning and filtering mechanisms.

Patching and Updates

Apply patches provided by SquirrelMail to address the vulnerability and enhance system security.