The Serialize.deserialize() method in CoAPthon 3.1, 4.0.0, 4.0.1, and 4.0.2 mishandles certain exceptions, leading to a denial of service in applications that use this library (e.g., the standard CoAP server, CoAP client, CoAP reverse proxy, example collect CoAP server and client) when they receive crafted CoAP messages.
Weakness
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Coapthon | Coapthon_project | 3.1 (including) | 3.1 (including) |
| Coapthon | Coapthon_project | 4.0.0 (including) | 4.0.0 (including) |
| Coapthon | Coapthon_project | 4.0.1 (including) | 4.0.1 (including) |
| Coapthon | Coapthon_project | 4.0.2 (including) | 4.0.2 (including) |
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.