c3p0 is a JDBC Connection pooling library. In versions prior to 0.14.0, c3p0 in combination with other libraries, can compose to a sink for deserialization gadgets. The JDBC specs DataSource.getConnection() and ConnectionPoolDataSource.getPooledConnection() match the getXXX() form, so JavaBean libraries treat them as properties assumed safe while they actually call into JDBC drivers. Attackers can thus craft malicious DataSource objects whose property lookups invoke vulnerable drivers, then smuggle them in serialized form to where an application deserializes and auto-resolves bean properties — triggering the attack. This requires a susceptible DataSource/ConnectionPoolDataSource and JDBC driver on the CLASSPATH, plus a carrier that auto-looks-up JavaBean properties on = deserialization, most commonly a collection paired with an Apache commons-beanutils Comparator that sorts by bean properties. c3p0 supplied that susceptible DataSource/ConnectionPoolDataSource, which was an essential component of the trigger. This issue has been fixed in version 0.14.0.
Weakness
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Red Hat build of Apache Camel 4.18.3 for Spring Boot 3.5.16 | RedHat | c3p0 | * |
| C3p0 | Ubuntu | questing | * |
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.