ePA 3.x Integration: AES-GCM Nonce Reuse via Frozen VAU Request Counter
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| fbeta-GmbH | ePA3-Service-OpenSource | affected |
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No data.
No data.
| Vendor | Product | Versions | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Fbeta-gmbh | Epa3-service-opensource |
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No CVSS v4.0
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.513% probability within 30 days)
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Fbeta-gmbh
Fbeta-gmbh epa3-service-opensource |
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| Vendors & Products |
Fbeta-gmbh
Fbeta-gmbh epa3-service-opensource |
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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| Type | Values Removed | Values Added |
|---|---|---|
| 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 leaves request_counter unchanged in app/vau/VAUProtokoll.py while constructing VAU messages. The frozen client request counter causes the server side to reuse AES-GCM nonce and key combinations across responses. A network attacker who collects repeated ciphertexts can recover the XOR of plaintexts and use predictable inner HTTP headers and JSON fields to recover sensitive data, including patient health records. Repeated nonces can also enable recovery of the GHASH authentication key through the Joux forbidden attack, allowing forged AES-GCM messages and injection of malicious responses. The response-counter check also fails to maintain last_response_counter, weakening replay and ordering validation. This issue is fixed in version 1.3.0. | |
| Title | ePA 3.x Integration: AES-GCM Nonce Reuse via Frozen VAU Request Counter | |
| Weaknesses | CWE-323 | |
| References |
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| Metrics |
cvssV3_1
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