The vulnerability stems from insecure deserialization in message handling. Analysis of the technical blog reveals: 1) Messages are Base64 decoded then deserialized via Hessian2Input 2) The deserializeFromString method directly processes untrusted data 3) SQSConnector's message conversion pipeline lacks validation before deserialization. This matches the CWE-862 (Missing Authorization) as no security checks validate() message authenticity/safety before processing. The Hessian deserialization vulnerability pattern directly enables command injection through crafted object payloads.