Drupal Email TFA: Urgent Security Update – Authentication Bypass (CVE-2025-12760)

Overview

This blog post provides an in-depth analysis of CVE-2025-12760, a critical authentication bypass vulnerability affecting the Email TFA (Two-Factor Authentication) module for Drupal. This vulnerability allows a potential attacker to bypass the two-factor authentication mechanism, potentially gaining unauthorized access to user accounts. It affects Email TFA versions before 2.0.6.

Technical Details

CVE-2025-12760 is classified as an “Authentication Bypass Using an Alternate Path or Channel” vulnerability. The specific details of the vulnerability are not explicitly described in the initial announcement but indicate that a flaw in the module’s logic allows authentication to proceed without proper validation of the TFA code, potentially by exploiting an alternative, unintended authentication path or channel. The lack of proper validation of the TFA code allows an attacker to bypass this security measure and gain unauthorized access.

Without further information the precise bypass mechanism is unknown, but the patch likely addresses an oversight in the authentication workflow.

CVSS Analysis

Currently, the CVSS score for CVE-2025-12760 is listed as N/A (Not Available). This indicates that either the severity has not yet been formally assessed or there are complexities preventing an accurate score calculation. However, given that this is an authentication bypass vulnerability in a two-factor authentication module, it should be considered a high-severity risk until a formal score is available. This means it could lead to complete compromise of an affected account and potentially the entire system.

Possible Impact

The exploitation of CVE-2025-12760 could have significant consequences:

• Account Takeover: Attackers can bypass the two-factor authentication mechanism, gaining unauthorized access to user accounts.
• Data Breach: Compromised accounts can be used to access sensitive data stored within the Drupal site.
• Website Defacement: Attackers can modify the website’s content, damaging its reputation.
• Malware Distribution: Compromised accounts can be used to distribute malware to other users of the site.
• Denial of Service: An attacker could potentially disrupt services for legitimate users.

Mitigation and Patch Steps

The most critical step is to update the Email TFA module to version 2.0.6 or later as soon as possible. Here’s how:

1. Backup Your Drupal Site: Before applying any updates, create a complete backup of your Drupal site, including the database and all files.
2. Update the Email TFA Module: Use Drupal’s built-in update manager or Drush to update the Email TFA module to version 2.0.6 or later.
   • Using Drupal’s Update Manager: Navigate to “Extend” -> “Updates” in your Drupal administration panel. Check for available updates and install the update for the Email TFA module.
   • Using Drush: Run the following command: drush updatdb -y and then drush cr
3. Verify the Update: After the update is complete, verify that the Email TFA module is running version 2.0.6 or later by checking the module’s listing in the “Extend” section.
4. Monitor Logs: Monitor your Drupal site’s logs for any suspicious activity following the update.

References

• Drupal Security Advisory: SA-CONTRIB-2025-115