Adaptive Chosen-Ciphertext Attacks
There are 2 attack subtypes.
Prerequisites for attack
The following prerequisites are needed to execute the attacks:
- Attacker can reach endpoint from its location.
- Attacker is in possession of an encrypted SOAP message.
- Attacker can modify the ciphertext inside the message and this modification is not rejected by the server. This means the ciphertext is not signed or the attacker can execute further attacks (e.g. XML Signature Wrapping) to modify the signed ciphertext.
- The server responds with 1 or 0 according to the validity of the decrypted message. The different messages can for example be a result of incorrect decryption processing or parsing of the decrypted message.
Graphical representation of attack
The attack targets the decryption component of a Web Service, in combination with the application logic (if the ciphertext is correctly decrypted, the attacker can get information based on the error messages coming from the application logic).
- Red = attacked web service component
- Black = location of attacker
- Blue = web service component not directly involved in attack.
Attack mitigation / countermeasures
Categorisation by violated security objective
Categorisation by number of involved parties
Categorisation by attacked component in web service architecture
- Category:Attack Categorisation By Attacked Web Service Component: Decryption
Categorisation by attack spreading
- Category:Attack Categorisation By Attack Spreading:Conceptual Flaws