CVE-2021-24579

The bt_bb_get_grid AJAX action of the Bold Page Builder WordPress plugin before 3.1.6 passes user input into the unserialize() function without any validation or sanitisation, which could lead to a PHP Object Injection. Even though the plugin did not contain a suitable gadget to fully exploit the issue, other installed plugins on the blog could allow such issue to be exploited and lead to RCE in some cases.

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/08edce3f-2746-4886-8439-76e44ec76fa8
• https://wpscan.com/vulnerability/08edce3f-2746-4886-8439-76e44ec76fa8