CVE-2019-18336 Explained : Impact and Mitigation

A security flaw has been discovered in various Siemens products, including SIMATIC S7-300 CPU family, SIMATIC TDC CP51M1, SIMATIC TDC CPU555, and SINUMERIK 840D sl. These vulnerabilities exist in all versions prior to V3.X.17, V1.1.8, V1.1.1, V4.8.6, and V4.94 respectively. If an attacker sends specially crafted packets to port 102/tcp (Profinet), it can trigger a defect mode on the affected device. To recover the system, a restart is necessary. The exploitation does not require any user interaction or authentication. As of the advisory publication, there have been no reported cases of public exploitation of this security vulnerability.

Understanding CVE-2019-18336

A vulnerability affecting Siemens products that could lead to a defect mode on the device when receiving malicious packets.

What is CVE-2019-18336?

CVE-2019-18336 is a security vulnerability found in Siemens products, allowing attackers to disrupt the system by sending specific packets to a designated port.

The Impact of CVE-2019-18336

Attackers can remotely trigger a defect mode on affected devices without requiring user interaction or authentication.
The vulnerability could lead to system downtime and potential disruptions in industrial processes.

Technical Details of CVE-2019-18336

A detailed look at the vulnerability and its implications.

Vulnerability Description

The vulnerability allows attackers to exploit Siemens products by sending crafted packets to port 102/tcp, causing the device to enter a defect mode.

Affected Systems and Versions

SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants): All versions < V3.X.17
SIMATIC TDC CP51M1: All versions < V1.1.8
SIMATIC TDC CPU555: All versions < V1.1.1
SINUMERIK 840D sl: All versions < V4.8.6 and V4.94

Exploitation Mechanism

Attackers exploit the vulnerability by sending specially crafted packets to port 102/tcp (Profinet).
No user interaction or authentication is required for successful exploitation.

Mitigation and Prevention

Steps to mitigate the CVE-2019-18336 vulnerability.

Immediate Steps to Take

Apply vendor-supplied patches or updates to affected systems.
Implement network segmentation to restrict access to critical ports.
Monitor network traffic for any suspicious activity targeting port 102/tcp.

Long-Term Security Practices

Regularly update and patch all industrial control systems to prevent known vulnerabilities.
Conduct security assessments and penetration testing to identify and address potential weaknesses.

Patching and Updates

Siemens may release patches or updates to address the vulnerability; ensure timely installation to secure the systems.