CVE-2018-6198 : Security Advisory and Response

CVE-2018-6198 was published on January 25, 2018, and affects versions up to 0.5.3 of the w3m web browser. The vulnerability arises from improper handling of temporary files when the ~/.w3m directory is unwritable, enabling a local attacker to execute a symlink attack and overwrite any file.

Understanding CVE-2018-6198

This CVE entry highlights a security flaw in w3m versions up to 0.5.3 that can be exploited by a local attacker to perform unauthorized file overwrites through symlink attacks.

What is CVE-2018-6198?

CVE-2018-6198 is a vulnerability in w3m versions up to 0.5.3 that allows a local attacker to manipulate temporary files and conduct symlink attacks to overwrite arbitrary files on the system.

The Impact of CVE-2018-6198

The vulnerability in w3m versions up to 0.5.3 poses a significant risk as it enables a local attacker to compromise the integrity and confidentiality of files on the system through symlink attacks.

Technical Details of CVE-2018-6198

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The flaw in w3m versions up to 0.5.3 arises from the improper handling of temporary files when the ~/.w3m directory is unwritable, allowing a local attacker to craft symlink attacks to overwrite any file on the system.

Affected Systems and Versions

Product: w3m
Vendor: N/A
Versions affected: Up to 0.5.3

Exploitation Mechanism

The vulnerability can be exploited by a local attacker who can manipulate the ~/.w3m directory to perform symlink attacks and overwrite files on the system.

Mitigation and Prevention

Protecting systems from CVE-2018-6198 involves immediate steps and long-term security practices.

Immediate Steps to Take

Ensure the ~/.w3m directory is properly configured and writable to authorized users only.
Monitor file permissions and restrict access to critical directories.
Regularly audit and review file changes for any unauthorized modifications.

Long-Term Security Practices

Implement the principle of least privilege to restrict user access to sensitive directories.
Keep software and systems updated to prevent known vulnerabilities from being exploited.

Patching and Updates

Apply patches or updates provided by the vendor to address the vulnerability in w3m versions up to 0.5.3.