A Polymorphic Typing issue was discovered in FasterXML jackson-databind 2.x through 2.9.9. When Default Typing is enabled (either globally or for a specific property) for an externally exposed JSON endpoint and the service has JDOM 1.x or 2.x jar in the classpath, an attacker can send a specifically crafted JSON message that allows them to read arbitrary local files on the server.
{ "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "2.4.2-3ubuntu0.1~esm2", "binary_name": "libjackson2-databind-java" }, { "binary_version": "2.4.2-3ubuntu0.1~esm2", "binary_name": "libjackson2-databind-java-doc" } ] }