One Insecure Deserialization can Expose Enterprise Systems

**Insecure Deserialization (CWE-502)** is a persistent, high-impact application-layer vulnerability that allows attackers to manipulate serialized objects to achieve remote code execution, SSRF, denial-of-service, and privilege escalation. The report explains serialization/deserialization mechanics, common enterprise attack vectors and gadget-chain exploitation (across Java, PHP, Python, .NET), cites historical high-profile incidents (Equifax, Oracle WebLogic, Jenkins), and provides defensive guidance—avoid native deserialization, allowlist classes, verify integrity with signatures, sandbox deserialization, and integrate tests and training into the SDLC.