CVE-2019-13173 : Security Advisory and Response
Learn about CVE-2019-13173, a vulnerability in fstream version prior to 1.0.12 allowing Arbitrary File Overwrite. Find out the impact, affected systems, exploitation mechanism, and mitigation steps.
A vulnerability in fstream version prior to 1.0.12 allows for Arbitrary File Overwrite when extracting tarballs. Attackers can exploit this by using hardlinks to overwrite existing files on the system.
Understanding CVE-2019-13173
This CVE involves a vulnerability in fstream that enables attackers to overwrite files on the system.
What is CVE-2019-13173?
The vulnerability in fstream version prior to 1.0.12 allows for Arbitrary File Overwrite. Attackers can exploit this by extracting tarballs containing a hardlink pointing to an existing file on the system, along with a file that matches the hardlink. This results in overwriting the existing file on the system, with the vulnerability residing in the fstream.DirWriter() function.
The Impact of CVE-2019-13173
The impact of this vulnerability is the potential for attackers to overwrite critical files on the system, leading to data loss or unauthorized modifications.
Technical Details of CVE-2019-13173
This section provides technical details of the CVE.
Vulnerability Description
The vulnerability in fstream before 1.0.12 allows for Arbitrary File Overwrite. Extracting tarballs containing a hardlink to an existing file and a matching file will overwrite the system's file with the extracted file's contents. The vulnerable function is fstream.DirWriter().
Affected Systems and Versions
- Product: Not applicable
- Vendor: Not applicable
- Versions affected: Prior to 1.0.12
Exploitation Mechanism
- Attackers exploit the vulnerability by extracting tarballs with a hardlink to an existing file and a matching file, causing the system file to be overwritten.
Mitigation and Prevention
Protecting systems from CVE-2019-13173 is crucial.
Immediate Steps to Take
- Update fstream to version 1.0.12 or later to mitigate the vulnerability.
- Avoid extracting tarballs from untrusted sources.
Long-Term Security Practices
- Regularly update software and dependencies to patch known vulnerabilities.
- Implement file integrity monitoring to detect unauthorized changes.
Patching and Updates
- Apply patches and updates provided by the software vendor to address security issues.