CVE-2017-6927 : Vulnerability Insights and Analysis

Drupal Core versions prior to 8.4.5 and Drupal 7.x versions before 7.57 are vulnerable to a cross-site scripting issue related to the JavaScript function Drupal.checkPlain(). Learn about the impact, technical details, and mitigation steps.

Understanding CVE-2017-6927

Drupal Core versions prior to 8.4.5 and Drupal 7.x versions before 7.57 are affected by a cross-site scripting vulnerability due to inadequate handling of malicious HTML injection.

What is CVE-2017-6927?

Versions of Drupal 8.4.x before 8.4.5 and Drupal 7.x before 7.57 have a vulnerability in the Drupal.checkPlain() JavaScript function, which fails to properly handle certain methods of injecting harmful HTML, potentially leading to cross-site scripting attacks.

The Impact of CVE-2017-6927

The vulnerability allows attackers to execute malicious scripts in the context of the victim's browser, leading to potential data theft, session hijacking, and other harmful activities.
This issue poses a significant risk to websites and web applications built on affected Drupal versions.

Technical Details of CVE-2017-6927

Drupal Core's vulnerability to cross-site scripting

Vulnerability Description

The issue arises from the inadequate handling of HTML escaping in the Drupal.checkPlain() function, allowing attackers to inject malicious scripts into web pages.

Affected Systems and Versions

Drupal 8.4.x versions before 8.4.5
Drupal 7.x versions before 7.57

Exploitation Mechanism

Attackers can exploit this vulnerability by injecting malicious HTML code into specific contexts, potentially leading to the execution of unauthorized scripts on the victim's browser.

Mitigation and Prevention

Protecting your systems from CVE-2017-6927

Immediate Steps to Take

Update Drupal Core to version 8.4.5 or later for Drupal 8.x users, and version 7.57 or later for Drupal 7.x users to mitigate the vulnerability.
Monitor web applications for any signs of unauthorized script execution or unusual behavior.

Long-Term Security Practices

Regularly apply security patches and updates to Drupal Core and associated modules to address known vulnerabilities.
Implement content security policies (CSP) to mitigate the impact of cross-site scripting attacks.

Patching and Updates

Stay informed about security advisories from Drupal.org and promptly apply recommended patches to secure your Drupal installations.