Siemens Mendix Forgot Password Module

As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global).

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1. EXECUTIVE SUMMARY

• CVSS v3 5.3
• ATTENTION: Exploitable remotely/low attack complexity
• Vendor: Siemens
• Equipment: Mendix Forgot Password Module
• Vulnerability: Observable Discrepancy

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an unauthenticated remote attacker to determine if a user is valid or not, enabling a brute force attack with valid users.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following products of Siemens, are affected:

• Mendix Forgot Password (Mendix 7 compatible): All versions prior to V3.7.3.
• Mendix Forgot Password (Mendix 8 compatible): All versions prior to V4.1.3.
• Mendix Forgot Password (Mendix 9 compatible): All versions prior to V5.4.0.
• Mendix Forgot Password (Mendix 10 compatible): All versions prior to V5.4.0.

3.2 Vulnerability Overview

3.2.1 OBSERVABLE DISCREPANCY CWE-203

Applications using the affected module are vulnerable to user enumeration due to distinguishable responses. This could allow an unauthenticated remote attacker to determine if a user is valid or not, enabling a brute force attack with valid users.

CVE-2023-43623 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been assigned; the CVSS vector string is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N).

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

Siemens reported this vulnerability to CISA.

4. MITIGATIONS

Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk:

• Mendix Forgot Password (Mendix 7 compatible): Update to V3.7.3 or later version.
• Mendix Forgot Password (Mendix 8 compatible): Update to V4.1.3 or later version.
• Mendix Forgot Password (Mendix 9 compatible): Update to V5.4.0 or later version.
• Mendix Forgot Password (Mendix 10 compatible): Update to V5.4.0 or later version.

As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for industrial security and following recommendations in the product manuals.

Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage.

For more information see the associated Siemens security advisory SSA-295483 in HTML and CSAF.

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability, such as:

• Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.
• Locate control system networks and remote devices behind firewalls and isolating them from business networks.
• When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs). Recognize VPNs may have vulnerabilities, should be updated to the most recent version available, and are only as secure as the connected devices.

CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.

CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.

CISA also recommends users take the following measures to protect themselves from social engineering attacks:

• Do not click web links or open attachments in unsolicited email messages.
• Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
• Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.

No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time.

5. UPDATE HISTORY

• October 12, 2023: Initial Publication