Description

ePA 3.x Integration implements the authorization workflow and writes Medical Information Objects to Germany's electronic patient record. Prior to 1.3.0, ePA 3.x Integration disables TLS certificate verification for both ePA connections in app/vau/VAUProtokoll.py and Konnektor connections in app/konnektor/Konnektor.py. A network-positioned attacker can present an arbitrary certificate, terminate the TLS connection, and intercept ePA traffic. The VAU protocol does not provide an effective fallback because its application-layer certificate validation is also broken in affected versions. The Konnektor session uses self.session.verify set to False while the client authenticates with self.session.cert, so an attacker impersonating the Konnektor can receive the client's mutual TLS certificate exchange and observe smartcard operations. This issue is fixed in version 1.3.0.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-18T17:16:58.933Z",
  "pubdate": "2026-08-18T17:16:58.933Z",
  "executiveSummary": "ePA 3.x Integration contains a critical TLS certificate validation vulnerability prior to version 1.3.0.\nThe vulnerability involves the complete disabling of TLS certificate verification for both ePA connections and Konnektor connections.\nThis flaw allows a network-positioned attacker to execute Man-in-the-Middle attacks, intercept sensitive electronic patient record traffic, and observe smartcard operations during mutual TLS authentication.\nThe affected systems include the ePA 3.x Integration application, specifically impacting network communication handlers.\nAttackers require a network-positioned vantage point to intercept and manipulate traffic.\nThe risk implications are severe, exposing confidential medical information and authentication credentials.\nThe issue is fully resolved in version 1.3.0 by enforcing proper TLS validation.",
  "technicalDetails": "The root cause of the vulnerability stems from the explicit disabling of TLS certificate verification within the underlying communication logic of the ePA 3.x Integration software.\nSpecifically, certificate validation is bypassed for ePA connections inside app/vau/VAUProtokoll.py and for Konnektor connections inside app/konnektor/Konnektor.py.\nIn the Konnektor implementation, the HTTP session parameter self.session.verify is explicitly set to False.\nConcurrently, the client authenticates using self.session.cert, which results in a weakened security posture where the client transmits its mutual TLS certificate to an unverified server.\nFurthermore, the VAU protocol fails to provide an effective security fallback because its application-layer certificate validation mechanism is similarly broken in affected versions.\nThe step-by-step attack flow begins with a network-positioned attacker intercepting the communication channel between the client and the target endpoints.\nBecause TLS certificate verification is disabled, the client unconditionally accepts any arbitrary certificate presented by the attacker, thereby terminating the genuine TLS connection.\nThe attacker establishes a proxy position, decrypting and inspecting all transiting ePA traffic.\nIn interactions involving the Konnektor session, the attacker successfully impersonates the Konnektor endpoint, receives the client's mutual TLS certificate exchange, and observes sensitive smartcard operations without triggering validation errors.\nThe vulnerability affects all versions of ePA 3.x Integration prior to 1.3.0.\nExploitation requires network positioning along the communication path between the client and the ePA or Konnektor endpoints, but does not require prior authentication or elevated privileges."
}