CVE-2021-34572 : Vulnerability Insights and Analysis

CVE-2021-34572, also known as 'Insufficient Verification of Data Authenticity in Enbra EWM (replay attack),' is a vulnerability found in Enbra EWM 1.7.29. This CVE was reported to CERT@VDE by Libor POLČÁK. The vulnerability allows wireless M-Bus Security mode 5 devices to perform replay attacks due to a lack of proper detection mechanisms in the Enbra EWM system.

Understanding CVE-2021-34572

This section delves into the details of the vulnerability, its impact, technical aspects, and mitigation strategies.

What is CVE-2021-34572?

The CVE-2021-34572 vulnerability in Enbra EWM 1.7.29 arises from the system's failure to identify replay attacks conducted by wireless M-Bus Security mode 5 devices. As a result, the sensor timestamps are overwritten with the readout time, even when the data is a replay of previous information.

The Impact of CVE-2021-34572

The impact of this vulnerability is considered medium, with a CVSS base score of 6.5. While it does not affect confidentiality, it poses a high integrity impact as the sensor data may be manipulated or misrepresented through replay attacks.

Technical Details of CVE-2021-34572

Understanding the technical aspects and specifics of the vulnerability is crucial for effective mitigation.

Vulnerability Description

Enbra EWM 1.7.29 lacks the necessary checks to identify and prevent replay attacks by wireless M-Bus Security mode 5 devices. This allows attackers to replace sensor timestamps with current readout times, facilitating data manipulation.

Affected Systems and Versions

The specific version affected by CVE-2021-34572 is Enbra EWM 1.7.29 released on 03.11.2019.

Exploitation Mechanism

The vulnerability enables malicious actors with access to wireless M-Bus Security mode 5 devices to exploit replay attacks, manipulating sensor data timestamps.

Mitigation and Prevention

Mitigating CVE-2021-34572 requires immediate actions to secure systems and prevent potential exploitation.

Immediate Steps to Take

Organizations using Enbra EWM 1.7.29 should consider disabling or updating the affected version to address the vulnerability. Implementing access controls and encryption mechanisms can also help prevent unauthorized data modifications.

Long-Term Security Practices

Regular security audits, software updates, and employee training on cybersecurity best practices are essential for long-term protection against similar vulnerabilities.

Patching and Updates

Enbra should release a patch or update that includes validation checks for sensor data authenticity to prevent replay attacks and ensure the integrity of timestamps.