CVE-2019-6576 Explained : Impact and Mitigation

A security flaw has been discovered in various versions of Siemens AG's SIMATIC HMI Comfort Panels, SIMATIC HMI Comfort Outdoor Panels, SIMATIC HMI KTP Mobile Panels, SIMATIC WinCC Runtime Advanced, SIMATIC WinCC Runtime Professional, SIMATIC WinCC (TIA Portal), and SIMATIC HMI Classic Devices. This vulnerability allows attackers with network access to potentially acquire a TLS session key, compromising data confidentiality.

Understanding CVE-2019-6576

This CVE identifies a cryptographic issue affecting multiple Siemens AG products.

What is CVE-2019-6576?

The vulnerability allows attackers with network access to intercept TLS traffic between legitimate users and affected devices, potentially decrypting data and compromising communication confidentiality.

The Impact of CVE-2019-6576

Attackers can acquire TLS session keys, compromising data confidentiality.
Potential decryption of TLS traffic between legitimate users and affected devices.
Confidentiality of communication between devices and users at risk.
No reported instances of public exploitation at the time of advisory publication.

Technical Details of CVE-2019-6576

This section provides technical insights into the vulnerability.

Vulnerability Description

The flaw enables attackers with network access to potentially acquire TLS session keys, leading to data decryption.

Affected Systems and Versions

SIMATIC HMI Comfort Panels 4" - 22" (All versions < V15.1 Update 1)
SIMATIC HMI Comfort Outdoor Panels 7" & 15" (All versions < V15.1 Update 1)
SIMATIC HMI KTP Mobile Panels KTP400F, KTP700, KTP700F, KTP900 und KTP900F (All versions < V15.1 Update 1)
SIMATIC WinCC Runtime Advanced (All versions < V15.1 Update 1)
SIMATIC WinCC Runtime Professional (All versions < V15.1 Update 1)
SIMATIC WinCC (TIA Portal) (All versions < V15.1 Update 1)
SIMATIC HMI Classic Devices (TP/MP/OP/MP Mobile Panel) (All versions)

Exploitation Mechanism

Attacker needs network access to device's web interface.
Ability to monitor TLS traffic between legitimate users and the web interface.
Exploitation could compromise communication confidentiality.

Mitigation and Prevention

Protecting systems from CVE-2019-6576 is crucial.

Immediate Steps to Take

Apply vendor-provided patches and updates.
Monitor network traffic for any suspicious activity.
Restrict network access to affected devices.

Long-Term Security Practices

Regularly update and patch all software and firmware.
Implement network segmentation to limit exposure.
Conduct regular security assessments and audits.

Patching and Updates

Siemens AG has released patches to address the vulnerability.
Ensure all affected systems are updated to versions V15.1 Update 1 or higher.