Improper Verification of Cryptographic Signature in com.oviva.telematik:epa4all-client

Impact

An attacker who can MITM the TLS connection between the client and the IDP (within the TI network) can substitute a forged discovery document. The forged document redirects u ri_puk_idp_enc and uri_puk_idp_sig to attacker-controlled URLs. The client then encrypts the SMC-B-signed challenge response to the attacker's encryption key and POSTs it to the attacker's auth endpoint. This captures the signed authentication material.

Patches

#36

Workarounds

None.

Resources

• MS-OVIVA-EPA4ALL-d453c1

Credits

Machine Spirits (contact@machinespirits.de)

• Dr. rer. nat. Simon Weber
• Dipl.-Inf. Volker Schönefeld
• Chiara Fliegner