CVE-2018-6196 Explained : Impact and Mitigation

CVE-2018-6196, published on January 25, 2018, addresses a vulnerability in w3m up to version 0.5.3 related to infinite recursion in HTMLlineproc0.

Understanding CVE-2018-6196

What is CVE-2018-6196?

w3m up to version 0.5.3 is susceptible to an infinite recursion flaw in HTMLlineproc0 due to a lack of proper restriction for negative values in the feed_table_block_tag function in table.c.

The Impact of CVE-2018-6196

This vulnerability could be exploited to cause a denial of service (DoS) condition or potentially execute arbitrary code on the affected system.

Technical Details of CVE-2018-6196

Vulnerability Description

The issue arises from the feed_table_block_tag function in table.c not adequately restricting negative values for indentation, leading to infinite recursion in HTMLlineproc0.

Affected Systems and Versions

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

Exploitation Mechanism

The vulnerability can be exploited by crafting a malicious HTML file that triggers the infinite recursion flaw, potentially leading to a DoS or arbitrary code execution.

Mitigation and Prevention

Immediate Steps to Take

Apply the latest security updates provided by the vendor.
Avoid visiting untrusted websites or opening suspicious HTML files.
Consider using alternative browsers until a patch is available.

Long-Term Security Practices

Regularly update software and apply security patches promptly.
Implement network security measures to detect and block malicious traffic.

Patching and Updates

Ensure that the w3m software is updated to a version that includes a fix for the infinite recursion vulnerability.