Traffic interception via unauthenticated VAU server keys
Published Jul 24, 2026 · Updated Jul 24, 2026
Improper cryptographic verification in ePA4all before 2026-05-20 allows man-in-the-middle attackers to intercept and alter VAU traffic. In VAU Message 2, the client deserializes signatureEs256, certHash, and ocspResponse but never verifies the signed public keys, TI-PKI chain, revocation status, or VAU role OID. A network-path position between the application and ePA backend is required; successful interception exposes session keys, patient data, authorization tokens, and arbitrary request injection.
Summary
What happened
Improper cryptographic verification in ePA4all before 2026-05-20 allows man-in-the-middle attackers to intercept and alter VAU traffic. In VAU Message 2, the client deserializes signatureEs256, certHash, and ocspResponse but never verifies the signed public keys, TI-PKI chain, revocation status, or VAU role OID. A network-path position between the application and ePA backend is required; successful interception exposes session keys, patient data, authorization tokens, and arbitrary request injection.
The record
- CVE
- CVE-2026-48021
- Published
- Jul 24, 2026
- Updated
- Jul 24, 2026
- Vendor
- service health erx GmbH
- Product
- ePA4all
- Classifications
- CWE-347, T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 24, 2026CVE publishedPublication date reported by the CVE source.
- Jul 24, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 2026-05-20
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What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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