Insecure Deserialization occurs when untrusted data is deserialized by an application, allowing attackers to execute arbitrary code, manipulate objects, or cause denial-of-service. If user input is not validated or sanitized, many languages and frameworks are vulnerable to this issue because deserialization often involves reconstructing objects from serialized data, which can include malicious payloads.
Option A (".NET"): .NET applications (e.g., using BinaryFormatter or XmlSerializer) areprone to Insecure Deserialization if untrusted data is deserialized without validation. For example, BinaryFormatter can execute arbitrary code during deserialization, a well-known vulnerability (e.g., CVE-2017-11882).
Option B ("Java"): Java’s ObjectInputStream is notoriously vulnerable to Insecure Deserialization. Libraries like java.io.Serializable can execute code during deserialization of untrusted data, as seen in vulnerabilities like Apache Commons Collections (CVE-2015-7501).
Option C ("PHP"): PHP applications using functions like unserialize() are vulnerable if they deserialize untrusted input. For example, an attacker can craft a serialized object to trigger a gadget chain, leading to remote code execution (e.g., CVE-2016-7124).
Option D ("All of the above"): Correct, as .NET, Java, and PHP all have deserialization mechanisms that, if not properly secured, can lead to Insecure Deserialization vulnerabilities when handling untrusted input.
The correct answer is D, aligning with the CAP syllabus under "Insecure Deserialization" and "OWASP Top 10 (A08:2021 - Software and Data Integrity Failures)."References: SecOps Group CAP Documents - "Insecure Deserialization," "Serialization Security," and "OWASP Deserialization Cheat Sheet" sections.
