CVE-2021-24217

The run_action function of the Facebook for WordPress plugin before 3.0.0 deserializes user supplied data making it possible for PHP objects to be supplied creating an Object Injection vulnerability. There was also a useable magic method in the plugin that could be used to achieve remote code execution.

Weakness

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

Affected Software

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.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/586.html

References

• https://wpscan.com/vulnerability/509f2754-a1a1-4142-9126-ae023a88533a
• https://www.wordfence.com/blog/2021/03/two-vulnerabilities-patched-in-facebook-for-wordpress-plugin/
• https://wpscan.com/vulnerability/509f2754-a1a1-4142-9126-ae023a88533a
• https://www.wordfence.com/blog/2021/03/two-vulnerabilities-patched-in-facebook-for-wordpress-plugin/