CVE-2014-7209

What it actually does

The flaw permits arbitrary command execution when run-mailcap processes filenames containing unsanitized shell metacharacters, allowing injection into shell invocations triggered by MIME type handling.

Why it matters to the business

Systems relying on the vulnerable mime-support package face risk of remote or local command execution that can lead to data exposure, service disruption, or full system compromise; the package's widespread use in Debian-based environments increases operational exposure even years after disclosure.

How an attack unfolds

An attacker supplies a crafted filename embedding shell metacharacters to any code path invoking run-mailcap for MIME type lookup or file handling; because the filename is passed unsanitized into a shell command, the injected payload executes with the privileges of the calling process.

How to fix it

Upgrade the mime-support package to version 3.52-1+deb7u1 or later on all affected Debian releases; where immediate patching is not possible, restrict use of run-mailcap to trusted inputs or replace calls with safer MIME handling utilities.

How to confirm the fix worked

Verify installed package version with dpkg -l mime-support or apt-cache policy mime-support; confirm run-mailcap no longer processes metacharacters in test filenames after upgrade; scan source and configuration files for direct invocations of run-mailcap.

Typical attack path

1. Locate a Debian system with mime-support before 3.52-1+deb7u1
2. Identify an application or script that invokes run-mailcap with attacker-controlled filenames
3. Craft a filename containing shell metacharacters such as ;, |, or $()
4. Trigger the vulnerable code path to cause run-mailcap to process the filename
5. Execute arbitrary commands on the target system

How to detect it

Review process execution logs and audit trails for child processes spawned by run-mailcap or scripts that call it; inspect web or application logs for filenames containing shell metacharacters passed to MIME-handling routines; search command history and cron jobs for unexpected invocations involving mailcap.

What your security team should do

• Prioritize upgrade of mime-support across all Debian-based assets due to the package's foundational role in file handling
• Audit scripts and applications for any use of run-mailcap with untrusted filenames
• Implement input sanitization or switch to alternative MIME utilities where upgrades cannot be applied immediately
• Monitor package repositories for backported fixes on older Debian releases