CVE-2017-17042 : Vulnerability Insights and Analysis

YARD before version 0.9.11 is vulnerable to a directory traversal attack due to improper handling of relative paths.

Understanding CVE-2017-17042

The vulnerability in YARD allows attackers to read unauthorized files on the system.

What is CVE-2017-17042?

The server in YARD before version 0.9.11, specifically the lib/yard/core_ext/file.rb file, does not properly prevent relative paths starting with "../". This vulnerability enables attackers to perform directory traversal attacks and gain unauthorized access to read any files on the system.

The Impact of CVE-2017-17042

Attackers can exploit this vulnerability to conduct directory traversal attacks.
Unauthorized access to sensitive files on the system can be gained.

Technical Details of CVE-2017-17042

YARD vulnerability details and affected systems.

Vulnerability Description

lib/yard/core_ext/file.rb in the server in YARD before 0.9.11 does not block relative paths with an initial ../ sequence, allowing directory traversal attacks.

Affected Systems and Versions

Product: N/A
Vendor: N/A
Version: N/A

Exploitation Mechanism

Attackers can manipulate relative paths to access files outside the intended directory structure.

Mitigation and Prevention

Steps to mitigate and prevent exploitation of CVE-2017-17042.

Immediate Steps to Take

Update YARD to version 0.9.11 or newer to patch the vulnerability.
Implement input validation to block malicious path traversal attempts.

Long-Term Security Practices

Regularly monitor and audit file access permissions.
Educate developers on secure coding practices to prevent similar vulnerabilities.

Patching and Updates

Stay informed about security updates for YARD and apply patches promptly to address known vulnerabilities.