CVE-2019-18939 : Exploit Details and Defense Strategies

The eQ-3 Homematic CCU2 and CCU3 devices are vulnerable to remote code execution, allowing unauthenticated attackers to execute malicious code through specific scripts.

Understanding CVE-2019-18939

This CVE identifies a critical vulnerability in eQ-3 Homematic CCU2 and CCU3 devices that can be exploited by attackers with web interface access.

What is CVE-2019-18939?

The vulnerability in versions 2.47.20 of CCU2 and 3.47.18 of CCU3, when the HM-Print AddOn version 1.2a is installed, allows unauthenticated attackers to execute remote code through specific scripts.

The Impact of CVE-2019-18939

The vulnerability enables attackers to execute TCL script content via HTTP POST requests, potentially leading to unauthorized remote code execution.

Technical Details of CVE-2019-18939

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The flaw in eQ-3 Homematic CCU2 and CCU3 devices allows unauthenticated attackers to execute remote code through the exec.cgi and exec1.cgi scripts.

Affected Systems and Versions

eQ-3 Homematic CCU2 version 2.47.20
eQ-3 Homematic CCU3 version 3.47.18

Exploitation Mechanism

Attackers with web interface access can exploit the vulnerability by sending malicious TCL script content via HTTP POST requests.

Mitigation and Prevention

Protecting systems from CVE-2019-18939 requires immediate actions and long-term security practices.

Immediate Steps to Take

Disable remote access to the affected devices if not required
Apply vendor-supplied patches or updates promptly

Long-Term Security Practices

Regularly monitor and update firmware and software on the devices
Implement network segmentation to limit exposure to vulnerable devices

Patching and Updates

Check for security advisories from the vendor
Apply patches or updates provided by eQ-3 to address the vulnerability