CVE-2025-61505

e107 CMS thru 2.3.3 are vulnerable to insecure deserialization in the install.php script. The script processes user-controlled input in the previous_steps POST parameter using unserialize(base64_decode()) without validation, allowing attackers to craft malicious serialized data. This could lead to remote code execution, arbitrary file operations, or denial of service, depending on available PHP object gadgets in the codebase.

Weakness

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

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://github.com/e107inc/e107/blob/master/install.php
• https://xancatos.org/cve202561505