CVE-2019-13939 : Exploit Details and Defense Strategies

A security flaw has been discovered in various versions of Siemens products, including APOGEE MEC/MBC/PXC (P2), APOGEE PXC Series, Desigo PXC series, Nucleus NET, SIMOTICS CONNECT 400, TALON TC Series, and VSTAR. This vulnerability allows attackers to manipulate DHCP packets, potentially compromising device availability and integrity.

Understanding CVE-2019-13939

This CVE identifies a critical security vulnerability affecting multiple Siemens products.

What is CVE-2019-13939?

The vulnerability in Siemens products allows attackers to modify device IP addresses by manipulating DHCP packets, impacting device availability and integrity.

The Impact of CVE-2019-13939

The vulnerability could lead to a compromise in the availability and integrity of affected devices, posing a significant security risk.

Technical Details of CVE-2019-13939

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The flaw allows attackers to change device IP addresses to invalid values by sending specially crafted DHCP packets.

Affected Systems and Versions

APOGEE MEC/MBC/PXC (P2): All versions < V2.8.2
APOGEE PXC Series (BACnet): All versions < V3.5.3
Desigo PXC series: All versions >= V2.3x and < V6.00.327
Nucleus NET, Nucleus RTOS, Nucleus Source Code: All versions
SIMOTICS CONNECT 400: All versions < V0.3.0.330
TALON TC Series (BACnet): All versions < V3.5.3
VSTAR: All versions

Exploitation Mechanism

To exploit the vulnerability, attackers need access to the adjacent network to send manipulated DHCP packets without requiring authentication or user interaction.

Mitigation and Prevention

Protect your systems from CVE-2019-13939 with the following measures:

Immediate Steps to Take

Apply security patches provided by Siemens promptly.
Monitor network traffic for any suspicious DHCP packet activity.

Long-Term Security Practices

Implement network segmentation to limit the impact of potential attacks.
Regularly update and patch all affected Siemens products.
Conduct security assessments and audits to identify and address vulnerabilities.

Patching and Updates

Ensure all affected systems are updated with the latest patches and firmware releases to mitigate the risk of exploitation.