CVE-2017-6921 Explained : Impact and Mitigation
Learn about CVE-2017-6921 affecting Drupal Core before version 8.3.4. Understand the impact, exploitation mechanism, and mitigation steps for this security vulnerability.
Drupal Core before version 8.3.4 has a vulnerability in the file REST resource that allows certain fields to be manipulated without proper validation, potentially leading to unauthorized access.
Understanding CVE-2017-6921
Drupal Core version 8.3.4 and below are affected by a security flaw in the file REST resource, impacting websites with specific module configurations.
What is CVE-2017-6921?
- Drupal 8 prior to version 8.3.4 has a vulnerability in the file REST resource related to file manipulation validation.
- The issue arises when the RESTful Web Services (rest) module is active, allowing PATCH requests on the file REST resource.
- Attackers can exploit this by gaining or creating a user account with file manipulation permissions.
The Impact of CVE-2017-6921
- Attack Complexity: High
- Attack Vector: Physical
- Privileges Required: High
- User Interaction: Required
- CVSS Base Score: 0
- The vulnerability can result in access bypass on affected Drupal websites.
Technical Details of CVE-2017-6921
Drupal Core's vulnerability in the file REST resource can have severe consequences if not addressed promptly.
Vulnerability Description
- The file REST resource in Drupal 8 does not adequately validate certain fields during file operations.
Affected Systems and Versions
- Product: Drupal Core
- Vendor: Drupal
- Versions Affected: Drupal 8 versions less than 8.3.4
Exploitation Mechanism
- Requires the RESTful Web Services (rest) module to be active
- Allows PATCH requests on the file REST resource
- Attacker needs a user account with file manipulation permissions
Mitigation and Prevention
Taking immediate action and implementing long-term security measures are crucial to mitigate the risks associated with CVE-2017-6921.
Immediate Steps to Take
- Update Drupal Core to version 8.3.4 or later to patch the vulnerability.
- Disable the RESTful Web Services (rest) module if not essential for website functionality.
Long-Term Security Practices
- Regularly monitor and apply security updates for Drupal Core and its modules.
- Conduct security audits to identify and address potential vulnerabilities.
Patching and Updates
- Stay informed about security advisories from Drupal and promptly apply recommended patches.