CVE Vulnerabilities

CVE-2024-4157

Deserialization of Untrusted Data

Published: May 22, 2024 | Modified: Feb 06, 2025
CVSS 3.x
8.8
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu

The Contact Form Plugin by Fluent Forms for Quiz, Survey, and Drag & Drop WP Form Builder plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 5.1.15 via deserialization of untrusted input in the extractDynamicValues function. This makes it possible for authenticated attackers, with contributor-level access and above, to inject a PHP Object. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code. Successful exploitation requires the attacker to have View Form and Manage Form permissions, which must be explicitly set by an administrator. However, this requirement can be bypassed when this vulnerability is chained with CVE-2024-2771.

Weakness

The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.

Affected Software

Name Vendor Start Version End Version
Contact_form Fluentforms * 5.1.16 (excluding)

Extended Description

It is often convenient to serialize objects for communication or to save them for later use. However, deserialized data or code can often be modified without using the provided accessor functions if it does not use cryptography to protect itself. Furthermore, any cryptography would still be client-side security – which is a dangerous security assumption. Data that is untrusted can not be trusted to be well-formed. When developers place no restrictions on “gadget chains,” or series of instances and method invocations that can self-execute during the deserialization process (i.e., before the object is returned to the caller), it is sometimes possible for attackers to leverage them to perform unauthorized actions, like generating a shell.

Potential Mitigations

  • Make fields transient to protect them from deserialization.
  • An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

References