CVE-2018-19787 : Vulnerability Insights and Analysis

A vulnerability was found in lxml versions prior to 4.2.5 where the removal of javascript: URLs is not properly performed, potentially leading to XSS attacks.

Understanding CVE-2018-19787

A flaw in lxml.html.clean module allows malicious actors to exploit the vulnerability for XSS attacks.

What is CVE-2018-19787?

The vulnerability exists in lxml versions before 4.2.5
It stems from improper handling of javascript: URLs in the lxml.html.clean module
Exploitation could result in XSS attacks
Similar to CVE-2014-3146

The Impact of CVE-2018-19787

Malicious actors can execute XSS attacks by utilizing javascript: URLs
Particularly exploitable in Internet Explorer

Technical Details of CVE-2018-19787

A detailed look at the technical aspects of the vulnerability

Vulnerability Description

Found in lxml versions prior to 4.2.5
Specifically in lxml.html.clean module
Inadequate removal of javascript: URLs when escaping is used
Allows malicious actors to conduct XSS attacks

Affected Systems and Versions

Affected versions: prior to 4.2.5
Systems using lxml library before the patched version

Exploitation Mechanism

Malicious actors can exploit the vulnerability by injecting javascript: URLs
Particularly effective in Internet Explorer

Mitigation and Prevention

Measures to address and prevent the CVE-2018-19787 vulnerability

Immediate Steps to Take

Update lxml library to version 4.2.5 or newer
Implement input validation to mitigate XSS risks

Long-Term Security Practices

Regularly update software libraries and dependencies
Conduct security audits to identify and address vulnerabilities

Patching and Updates

Stay informed about security updates for lxml library
Apply patches promptly to prevent exploitation