CVE-2021-23859 : Exploit Details and Defense Strategies

A critical Denial of Service (DoS) and Authentication Bypass vulnerability has been identified in multiple Bosch products, allowing an unauthenticated attacker to crash services and potentially execute unauthorized commands.

Understanding CVE-2021-23859

This CVE relates to a severe vulnerability that affects various Bosch products, posing a significant security risk to users.

What is CVE-2021-23859?

The CVE-2021-23859 vulnerability allows an unauthenticated attacker to send a specific HTTP request, leading to a service crash. In scenarios involving standalone VRM or BVMS with VRM installation, this crash enables the attacker to send additional unauthenticated commands.

The Impact of CVE-2021-23859

The impact of this vulnerability is deemed critical, with a CVSS base score of 9.1 (Critical). It has high availability and integrity impact, requiring no privileges for exploitation.

Technical Details of CVE-2021-23859

This section provides detailed technical insights into the vulnerability.

Vulnerability Description

The vulnerability arises due to improper handling of exceptional conditions, allowing attackers to disrupt services and potentially gain unauthorized access.

Affected Systems and Versions

The CVE-2021-23859 vulnerability impacts several Bosch products, including BVMS, DIVAR IP series, VRM, VRM Exporter, APE, AEC, and BIS. Specific versions of these products are affected, ranging from < 11.0 to <= 3.81, affecting both specified and custom versions.

Exploitation Mechanism

Attackers can exploit this vulnerability via a low attack complexity over a network, resulting in a high availability impact and critical base severity.

Mitigation and Prevention

To safeguard systems from potential exploitation, immediate and long-term security measures should be undertaken.

Immediate Steps to Take

Apply patches and security updates provided by Bosch promptly.
Restrict network access to vulnerable products and utilize firewalls to filter incoming traffic.

Long-Term Security Practices

Regularly update and monitor all Bosch products for security patches.
Implement network segmentation to limit the reach of potential attackers.

Patching and Updates

Regularly check for security advisories and updates from Bosch to address vulnerabilities and strengthen system security.