CVE-2018-6517 : Vulnerability Insights and Analysis

CVE-2018-6517, related to Chloride by Puppet, highlights an issue where host fingerprints for unknown hosts were added to the user's known_hosts file without verification before version 0.3.0.

Understanding CVE-2018-6517

What is CVE-2018-6517?

Prior to version 0.3.0, Chloride's use of net-ssh led to the inclusion of host fingerprints for unrecognized hosts into the user's known_hosts file without confirmation. This behavior was addressed in version 0.3.0.

The Impact of CVE-2018-6517

The vulnerability allowed unauthorized host fingerprints to be added to the user's known_hosts file, potentially leading to security risks and unauthorized access.

Technical Details of CVE-2018-6517

Vulnerability Description

The issue stemmed from Chloride's improper handling of the known_hosts file, allowing unverified host fingerprints to be added.

Affected Systems and Versions

Product: Chloride
Vendor: Puppet
Versions Affected: Prior to 0.3.0

Exploitation Mechanism

Unauthorized host fingerprints were added to the known_hosts file without user verification, potentially enabling malicious actors to impersonate hosts.

Mitigation and Prevention

Immediate Steps to Take

Users should update Chloride to version 0.3.0 or newer to prevent unauthorized modifications to the known_hosts file.
Regularly monitor the known_hosts file for any unauthorized entries.

Long-Term Security Practices

Implement strict host key verification practices to ensure only trusted hosts are added to the known_hosts file.
Educate users on the importance of verifying host fingerprints before adding them to known_hosts.

Patching and Updates

Puppet users should regularly check for updates and apply patches promptly to address security vulnerabilities.