CVE-2019-10942 : Vulnerability Insights and Analysis

A security issue has been found in various models of the SCALANCE X-200 switch family (including SIPLUS NET variants) with versions lower than V5.2.5, the SCALANCE X-200IRT switch family (including SIPLUS NET variants) with versions lower than V5.5.0, SCALANCE X204RNA (HSR) in all versions, SCALANCE X204RNA (PRP) in all versions, SCALANCE X204RNA EEC (HSR) in all versions, SCALANCE X204RNA EEC (PRP) in all versions, and SCALANCE X204RNA EEC (PRP/HSR) in all versions. This vulnerability enables an attacker to cause a denial-of-service situation by repeatedly sending large message packages to the telnet service. The attacker must have network access to the affected systems in order to exploit this security flaw. Exploiting the vulnerability does not require any system privileges or user interaction. If successful, an attacker could disrupt the availability of the device.

Understanding CVE-2019-10942

This CVE identifies a vulnerability in Siemens SCALANCE X-200 and X-200IRT switch families, as well as specific SCALANCE X204RNA models, allowing for a denial-of-service attack.

What is CVE-2019-10942?

The CVE-2019-10942 vulnerability allows attackers to trigger a denial-of-service condition by sending large message packages to the telnet service on affected Siemens devices.

The Impact of CVE-2019-10942

Attackers can disrupt the availability of the affected devices without requiring system privileges or user interaction.

Technical Details of CVE-2019-10942

Siemens SCALANCE devices are affected by this vulnerability, impacting various models and versions.

Vulnerability Description

CWE-400: Uncontrolled Resource Consumption vulnerability in SCALANCE X-200 and X-200IRT switch families, and SCALANCE X204RNA models.

Affected Systems and Versions

SCALANCE X-200 switch family (incl. SIPLUS NET variants) - All versions < V5.2.5
SCALANCE X-200IRT switch family (incl. SIPLUS NET variants) - All versions < V5.5.0
SCALANCE X204RNA (HSR) - All versions
SCALANCE X204RNA (PRP) - All versions
SCALANCE X204RNA EEC (HSR) - All versions
SCALANCE X204RNA EEC (PRP) - All versions
SCALANCE X204RNA EEC (PRP/HSR) - All versions

Exploitation Mechanism

Attackers exploit the vulnerability by sending large message packages to the telnet service, causing a denial-of-service condition.

Mitigation and Prevention

Steps to address and prevent the CVE-2019-10942 vulnerability:

Immediate Steps to Take

Apply vendor-provided patches or updates to mitigate the vulnerability.
Implement network segmentation to limit access to affected devices.

Long-Term Security Practices

Regularly monitor network traffic for any unusual patterns that may indicate an ongoing attack.
Conduct security assessments and penetration testing to identify and address vulnerabilities proactively.

Patching and Updates

Stay informed about security advisories from Siemens and apply patches promptly to secure the affected devices.