39 Attack Vectors Undermine Passkey Authentication Trust
Researchers have identified 39 methods to compromise passkey-based authentication systems by exploiting trust boundaries in enrollment, recovery, and user verification workflows — not by breaking FIDO2 cryptography itself. This is critical because organizations adopting passkeys may develop a false sense of security, believing the underlying cryptographic standard alone is sufficient protection. Malware can manipulate WebAuthn infrastructure to generate signed assertions, effectively allowing attackers to authenticate without ever touching the private key. The root cause lies in misconfigured or insufficiently hardened authentication pipelines and inadequate controls around the processes that surround the cryptographic core. This highlights that strong algorithms alone cannot compensate for weak implementation and operational security around authentication systems.
Tactical Insight
Immediate actions
- Audit all passkey enrollment and recovery workflows to identify trust boundary weaknesses that could be exploited by malware or social engineering.
- Harden endpoint environments where WebAuthn clients operate by deploying EDR solutions capable of detecting manipulation of authentication processes.
- Disable or restrict high-risk recovery mechanisms (e.g., SMS-based fallback) that bypass passkey security guarantees.
Long-term improvements
- Implement phishing-resistant MFA layered with device attestation and hardware security keys (e.g., FIDO2 with verified attestation) to reduce reliance on software-only implementations.
- Establish a formal authentication security review process that evaluates the full lifecycle — enrollment, storage, recovery, and revocation — not just the cryptographic protocol.
- Apply the principle of least privilege to authentication infrastructure components to limit the blast radius of a compromised WebAuthn relying party.
Detection measures
- Deploy behavioral monitoring on endpoints and authentication servers to detect anomalous assertion generation or unexpected WebAuthn API calls.
- Implement centralized logging of all authentication events, including failed attempts, device registrations, and recovery actions, with alerting on suspicious patterns.
- Conduct regular purple team exercises specifically targeting passkey authentication flows to validate detective and preventive controls.