Improper Verification of Cryptographic Signature in com.oviva.telematik:epa4all-client
High severity
GitHub Reviewed
Published
May 11, 2026
in
oviva-ag/epa4all-client
•
Updated May 15, 2026
Description
Published to the GitHub Advisory Database
May 15, 2026
Reviewed
May 15, 2026
Last updated
May 15, 2026
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
Credits
Machine Spirits (contact@machinespirits.de)
References