CVE-2019-18211

An issue was discovered in Orckestra C1 CMS through 6.6. The EntityTokenSerializer class in Composite.dll is prone to unvalidated deserialization of wrapped BinaryFormatter payloads, leading to arbitrary remote code execution for any low-privilege user.

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://github.com/Orckestra/C1-CMS-Foundation/commits/dev
• https://github.com/Orckestra/C1-CMS-Foundation/commits/dev