D-Link DIR-650IN - Authenticated Command Injection Vulnerability

The Flaw

The D-Link DIR-650IN Wireless N300 Router has a serious authenticated command injection vulnerability in its diagnostic functionalities. Specifically, the sysHost parameter is not properly sanitized. This allows attackers, even those with low-privilege access, to inject operating system commands.

What's at Risk

If exploited, an attacker can fully compromise the router. This includes the ability to read sensitive files such as /etc/passwd, which contains crucial information about user accounts on the system. This could lead to further attacks or unauthorized access to the network.

Patch Status

Currently, there is no CVE assigned to this vulnerability, which raises concerns about the visibility and urgency for a patch. Users should check the vendor's website for any updates or firmware patches that may address this issue.

Immediate Actions

To protect your device:

• Change default credentials immediately if you haven't done so.
• Monitor your router's logs for any suspicious activity.
• Consider disabling remote management features if not needed.
• Keep an eye on D-Link's official channels for any firmware updates that might mitigate this vulnerability.

Steps to Reproduce

For educational purposes, the following steps demonstrate how an attacker might exploit this vulnerability:

1. Log in to the router web interface.
2. Navigate to Management → Diagnostic.
3. Choose either Ping or Traceroute.
4. Input: google.com | cat /etc/passwd.
5. Click Apply.
6. The output will include the contents of /etc/passwd, revealing sensitive information.

Conclusion

This vulnerability highlights the importance of proper input sanitization in web applications. Users of the D-Link DIR-650IN should take immediate steps to secure their devices and remain vigilant for updates from the manufacturer.