CVE-2019-12789 : Exploit Details and Defense Strategies

A vulnerability has been identified in the Actiontec T2200H T2200H-31.128L.08 devices, which are distributed by Telus. Unauthorized individuals can exploit a specific key sequence to gain root access, enabling them to make permanent alterations to the device.

Understanding CVE-2019-12789

This CVE involves a security issue in Actiontec T2200H T2200H-31.128L.08 devices distributed by Telus, allowing attackers to gain root access and manipulate the device.

What is CVE-2019-12789?

Attackers can use a specific key sequence (Ctrl-) via a UART adapter to obtain root privileges.
Once root access is acquired, attackers can modify the filesystem, potentially rendering the device inoperable.

The Impact of CVE-2019-12789

Unauthorized individuals can execute permanent alterations to the device, including disabling vendor management capabilities and installing malicious code.

Technical Details of CVE-2019-12789

This section provides technical insights into the vulnerability.

Vulnerability Description

Attaching a UART adapter to the system board allows attackers to gain root access using a specific key sequence.

Affected Systems and Versions

Actiontec T2200H T2200H-31.128L.08 devices distributed by Telus are affected.

Exploitation Mechanism

Attackers exploit the Ctrl-\ key sequence via a UART adapter to access a root shell.

Mitigation and Prevention

Protecting systems from CVE-2019-12789 is crucial to prevent unauthorized access and device manipulation.

Immediate Steps to Take

Avoid connecting unauthorized UART adapters to the system board.
Implement strong access controls to prevent unauthorized physical access to devices.

Long-Term Security Practices

Regularly monitor and audit device access and modifications.
Educate users on the risks of unauthorized physical access to devices.

Patching and Updates

Apply security patches and updates provided by the device vendor to address this vulnerability.