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Deserialization

What is a Deserialization vulnerability?​

Serialization converts complex data structures into a stream of bytes that can be sent or received over a network. Deserialization restores the byte stream to a copy of the previously serialized object. The receiving application can then interact with this deserialized object.

Deserializing attacker-controlled data allows attackers to manipulate serialized objects and pass malicious data to the receiving application.

Alternative terms for Serialization/Deserialization are:

  • Marshaling, Unmarshaling
  • Pickling, Unpickling

Check out this video for a high-level explanation:

What is the impact of Deserialization vulnerabilities?​

Attackers can reuse existing application code in malicious ways which results in a wide range of vulnerabilities such as:

  • Code execution: An attacker can exploit deserialization vulnerabilities to execute arbitrary code on a target system, giving them control over the system and access to sensitive data.
  • Unauthorized access: An attacker can use deserialization vulnerabilities to access and manipulate data or functionality that they are not authorized to access, such as administrative functions or sensitive data.
  • Denial-of-service (DoS) attacks: An attacker can exploit deserialization vulnerabilities to cause DoS attacks, by overloading the system with large amounts of data or by manipulating the data in a way that causes the system to crash or become unresponsive.

How to prevent Deserialization vulnerabilities?​

To prevent deserialization vulnerabilities, it is important to follow security best practices and implement appropriate security measures, such as:

  • Avoid deserialization of untrusted data: Do not deserialize data from untrusted sources or unvalidated user input.
  • Use type checking and input validation: Verify the type and content of serialized data to ensure that it is valid and expected.
  • Use secure deserialization libraries and frameworks: Use secure deserialization libraries and frameworks that can help prevent deserialization vulnerabilities and provide additional security features, such as input validation and type checking.
  • Apply access controls: Apply access controls to limit the privileges and actions that deserialized data can perform, such as preventing it from executing arbitrary code or accessing sensitive resources.
  • Keep software up to date: Keep software and security protocols up to date, as new vulnerabilities and security patches are regularly released.

References​

Taxonomies​

Explanation & Prevention​

Training​

Last updated on by Stefan Streichsbier