CVE-2025-31674: Drupal Core Object Injection Vulnerability

CVE-2025-31674 Overview

CVE-2025-31674 is an Object Injection vulnerability affecting Drupal core, arising from improperly controlled modification of dynamically-determined object attributes. This flaw allows attackers to inject malicious objects into the application, potentially leading to unauthorized code execution, data manipulation, or other security compromises within affected Drupal installations.

Critical Impact

Authenticated attackers with low privileges can exploit this Object Injection vulnerability over the network to potentially achieve high confidentiality, integrity, and availability impacts on affected Drupal sites.

Affected Products

• Drupal core versions 8.0.0 through 10.3.12
• Drupal core versions 10.4.0 through 10.4.2
• Drupal core versions 11.0.0 through 11.0.11
• Drupal core versions 11.1.0 through 11.1.2

Discovery Timeline

• March 31, 2025 - CVE-2025-31674 published to NVD
• May 1, 2025 - Last updated in NVD database

Technical Details for CVE-2025-31674

Vulnerability Analysis

This vulnerability stems from improper handling of dynamically-determined object attributes within Drupal core, classified under CWE-915 (Improperly Controlled Modification of Dynamically-Determined Object Attributes) and CWE-913 (Improper Control of Dynamically-Managed Code Resources). When user-controlled input is insufficiently validated before being used to set object properties, attackers can manipulate the application's internal state by injecting arbitrary objects or modifying existing object attributes in unintended ways.

Object Injection vulnerabilities in PHP applications like Drupal can be particularly dangerous because they may enable attackers to trigger magic methods (__wakeup, __destruct, __toString) on attacker-controlled objects, potentially leading to property-oriented programming (POP) chains that result in remote code execution or other severe impacts.

Root Cause

The root cause of CVE-2025-31674 lies in insufficient validation and sanitization of user-supplied input before it is used to dynamically set object properties within Drupal core. This allows attackers to manipulate object attributes that should be immutable or controlled exclusively by the application, breaking the expected security model and enabling Object Injection attacks.

Attack Vector

The vulnerability is exploitable over the network by authenticated users with low privileges. While the attack complexity is considered high (requiring specific conditions to be met), successful exploitation does not require user interaction. An attacker would need to craft malicious input that, when processed by the vulnerable Drupal component, results in the injection or modification of object attributes in a way that compromises the application's security.

The attack typically involves:

1. Identifying an input vector that feeds into the vulnerable object attribute modification logic
2. Crafting a malicious payload containing serialized objects or property manipulation data
3. Submitting the payload through the identified vector
4. Triggering the deserialization or attribute modification to execute the attack chain

Detection Methods for CVE-2025-31674

Indicators of Compromise

• Unusual serialized data patterns in HTTP request parameters, particularly containing PHP object notation
• Unexpected object instantiation or magic method invocations in application logs
• Error messages related to class not found or unexpected object types in PHP logs
• Anomalous database modifications or file system changes following web requests

Detection Strategies

• Monitor web application firewall (WAF) logs for serialized PHP object patterns in request data
• Implement application-level logging to track object deserialization operations and attribute modifications
• Deploy SentinelOne Singularity to detect and alert on suspicious PHP process behavior indicative of exploitation
• Review access logs for authenticated sessions making unusual requests to endpoints handling dynamic data

Monitoring Recommendations

• Enable verbose logging for Drupal watchdog to capture detailed error and warning messages
• Configure SIEM rules to correlate authentication events with subsequent anomalous application behavior
• Monitor for unexpected child processes spawned by the PHP/web server process
• Set up alerts for file integrity monitoring on critical Drupal directories

How to Mitigate CVE-2025-31674

Immediate Actions Required

• Update Drupal core to version 10.3.13, 10.4.3, 11.0.12, or 11.1.3 depending on your current branch
• Review access logs for signs of exploitation attempts prior to patching
• Temporarily restrict access to authenticated features if immediate patching is not possible
• Implement WAF rules to filter requests containing suspicious serialized object patterns

Patch Information

Drupal has released security patches addressing this vulnerability in the following versions:

Administrators should apply updates immediately by following the standard Drupal update process. For detailed patch information and upgrade instructions, refer to the Drupal Security Advisory SA-CORE-2025-003.

Workarounds

• Restrict authenticated access to trusted users only until patches can be applied
• Implement additional input validation at the web server or WAF level to filter potentially malicious payloads
• Enable Drupal's built-in security modules and ensure they are properly configured
• Consider placing the site in maintenance mode if exploitation risk is deemed critical and patching cannot be performed immediately

# Update Drupal core using Composer
composer update drupal/core --with-dependencies

# Clear Drupal cache after update
drush cache:rebuild

# Verify installed version
drush status | grep "Drupal version"