CAPEC-477 - Signature Spoofing by Mixing Signed and Unsigned Content

An attacker exploits the underlying complexity of a data structure that allows for both signed and unsigned content, to cause unsigned data to be processed as though it were signed data.






  • Attack Methods 4
  • Protocol Manipulation
  • Analysis
  • API Abuse
  • Spoofing

High level: The attacker may need to continuously monitor a stream of signed data, waiting for an exploitable message to appear.

High level: Attacker must be able to create malformed data blobs and know how to insert them in a location that the recipient will visit.

Signer and recipient are using complex data storage structures that allow for a mix between signed and unsigned data

Recipient is using signature verification software that does not maintain separation between signed and unsigned data once the signature has been verified.

Ensure the application is fully patched and does not allow the processing of unsigned data as if it is signed data.