CVE-2019-13943 : Security Advisory and Response

A security flaw has been discovered in several versions of the EN100 Ethernet module, including the DNP3 variant, IEC 61850 variant (versions below V4.37), IEC104 variant, Modbus TCP variant, and PROFINET IO variant. The vulnerability lies in the web interface of these modules and could potentially be exploited by an attacker to carry out Cross-Site Scripting (XSS) attacks. By manipulating certain web pages, the attacker can cause the application to behave unexpectedly for legitimate users. It is important to note that the exploitation of this vulnerability does not require the attacker to have authentication credentials for the web interface. This means that the attacker could potentially read or modify the contents of the web application. As of the publication of this advisory, there have been no known instances of public exploitation of this security vulnerability.

Understanding CVE-2019-13943

This CVE identifies a vulnerability in Siemens AG's EN100 Ethernet modules that could lead to Cross-Site Scripting attacks.

What is CVE-2019-13943?

CVE-2019-13943 is a security vulnerability found in various versions of Siemens AG's EN100 Ethernet modules, allowing potential exploitation for XSS attacks through the web interface.

The Impact of CVE-2019-13943

The vulnerability could enable attackers to manipulate web pages, leading to unexpected behavior in the application for legitimate users. Unauthorized access to and modification of web application content is possible without authentication.

Technical Details of CVE-2019-13943

Siemens AG's EN100 Ethernet modules are affected by this vulnerability.

Vulnerability Description

The flaw in the web interface of the affected modules permits Cross-Site Scripting attacks, posing a risk to the integrity of the web application.

Affected Systems and Versions

EN100 Ethernet module DNP3 variant: All versions
EN100 Ethernet module IEC 61850 variant: All versions < V4.37
EN100 Ethernet module IEC104 variant: All versions
EN100 Ethernet module Modbus TCP variant: All versions
EN100 Ethernet module PROFINET IO variant: All versions

Exploitation Mechanism

The vulnerability allows attackers to conduct XSS attacks by modifying specific web pages, potentially compromising the application's behavior.

Mitigation and Prevention

Taking immediate steps and implementing long-term security practices are crucial to mitigate the risks associated with CVE-2019-13943.

Immediate Steps to Take

Monitor vendor communications for patches and updates
Restrict access to the web interface of the affected modules
Implement network segmentation to limit exposure

Long-Term Security Practices

Regularly update and patch affected systems
Conduct security assessments and penetration testing
Educate users on safe web browsing practices

Patching and Updates

Stay informed about security advisories and apply patches promptly to address the vulnerability in the affected EN100 Ethernet modules.