CVE-2021-38173 : Security Advisory and Response

Btrbk before version 0.31.2 is vulnerable to remote command execution due to the mishandling of SSH commands filtering via ssh_filter_btrbk.sh in authorized_keys file.

Understanding CVE-2021-38173

This CVE identifier marks a security flaw in Btrbk, potentially allowing attackers to execute arbitrary commands remotely.

What is CVE-2021-38173?

The vulnerability in Btrbk versions before 0.31.2 arises from improper filtering of SSH commands, enabling threat actors to execute arbitrary commands through the ssh_filter_btrbk.sh script.

The Impact of CVE-2021-38173

Exploitation of this vulnerability can lead to unauthorized command execution on affected systems, potentially resulting in data breaches, system compromise, and further exploitation of network resources.

Technical Details of CVE-2021-38173

CVE-2021-38173 involves the mishandling of remote hosts filtering SSH commands by Btrbk's ssh_filter_btrbk.sh script within the authorized_keys file.

Vulnerability Description

The vulnerability allows malicious actors to bypass proper SSH command filtering, executing unauthorized commands on the target system.

Affected Systems and Versions

Btrbk versions prior to 0.31.2 are impacted by this vulnerability, exposing systems to the risk of remote command execution.

Exploitation Mechanism

Attackers can exploit CVE-2021-38173 by manipulating the SSH commands filtered by ssh_filter_btrbk.sh, gaining unauthorized access to execute arbitrary commands remotely.

Mitigation and Prevention

It is crucial to take immediate action to prevent exploitation of this vulnerability.

Immediate Steps to Take

Update Btrbk to version 0.31.2 or the latest available release to patch the security flaw.
Restrict network access to critical systems to minimize exposure.

Long-Term Security Practices

Regularly monitor for security updates and apply patches promptly.
Implement network segmentation and least privilege access controls to limit the impact of potential security breaches.

Patching and Updates

Stay informed about security bulletins and advisories for Btrbk to ensure timely application of patches and updates.