CAPEC-485 - Signature Spoofing by Key Recreation

An attacker obtains an authoritative or reputable signer's private signature key by exploiting a cryptographic weakness in the signature algorithm or pseudorandom number generation and then uses this key to forge signatures from the original signer to mislead a victim into performing actions that benefit the attacker.

Severity

Likelihood

Confidentiality

Integrity

Availability

  • Attack Methods 5
  • Protocol Manipulation
  • Analysis
  • API Abuse
  • Brute Force
  • Spoofing

High level: Cryptanalysis of signature generation algorithm

High level: Reverse engineering and cryptanalysis of signature generation algorithm implementation and random number generation

High level: Ability to create malformed data blobs and know how to present them directly or indirectly to a victim.

An authoritative signer is using a weak method of random number generation or weak signing software that causes key leakage or permits key inference.

An authoritative signer is using a signature algorithm with a direct weakness or with poorly chosen parameters that enable the key to be recovered using signatures from that signer.

Ensure cryptographic elements have been sufficiently tested for weaknesses.