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The CGM CLININET system implements smart card authentication to control access, but a critical flaw exists in how this verification is performed. The authentication check is conducted entirely locally on the client device, rather than being enforced by the server. In practice, the system only verifies the certificate number provided by the client. It does not cryptographically validate the presence of the physical smart card or verify ownership of the associated private key. This means the server trusts the client’s assertion of identity based solely on the certificate number. An attacker who can obtain or guess a valid certificate number can present it to the system. Since the authentication is client-side, they can modify the client application or intercept the communication to supply this number. The server, performing no further checks, grants access as if the legitimate smart card were present. This bypasses the entire security intent of the two-factor smart card system, reducing it to a single factor—possession of the certificate number. The vulnerability is classified under CWE-603 (Use of Client-Side Authentication). With a CVSS v4.0 score of 9.0, it is considered critical, requiring adjacent network access but no privileges or user interaction. All versions of CGM CLININET are affected .
DailyCVE Form:
Platform: CGM CLININET
Version: All versions
Vulnerability : Client-side auth bypass
Severity: Critical
date: 2026-03-02
Prediction: March 2026 patch
What Undercode Say:
Analytics:
The vulnerability stems from a fundamental architectural flaw. The system does not follow the principle of never trusting client-side authentication checks. Below are commands and concepts illustrating the weakness.
Hypothetical example of the flawed client-side check
Imagine the client application sends a request like this:
Request from client to server
curl -X POST https://<clininet-server>/api/authenticate \
-H "Content-Type: application/json" \
-d '{"certificate_number": "1234567890"}'
The server, trusting this client-side check, simply logs the user in
without verifying the smart card's presence via a cryptographic challenge.
Response: 200 OK with Session Token
An attacker who knows the certificate number "1234567890" can replay this request.
Example of what the SERVER-SIDE validation SHOULD be (simplified) 1. Server sends a random challenge to the client. 2. The smart card signs the challenge with its private key. 3. Client sends back the signed challenge. 4. Server verifies the signature using the public key associated with the certificate number. This is MISSING in CVE-2025-30042.
Conceptual Python code showing the server's lack of verification (This is not actual CGM code, but illustrates the flaw) def authenticate_user(certificate_number_from_client): VULNERABLE CODE The server only checks if the certificate number exists in the database. It does NOT verify that the client actually possesses the corresponding private key. if database.check_if_certificate_number_exists(certificate_number_from_client): Authentication successful! Create a session. session = create_session_for_user(certificate_number_from_client) return session else: return "Authentication Failed" END VULNERABLE CODE
How Exploit:
- Reconnaissance: An attacker on the same network as a CGM CLININET client identifies the system and potentially captures network traffic to obtain a valid certificate number.
- Obtain Certificate Number: This could be done via network sniffing (if transmitted insecurely), social engineering, or by accessing a system where the number is stored insecurely (e.g., config files).
- Bypass Authentication: The attacker uses a modified client or a custom script to send an authentication request directly to the server, supplying only the stolen certificate number.
- Gain Unauthorized Access: The server accepts the certificate number without further validation, granting the attacker a valid session with the privileges of the legitimate user.
Protection from this CVE:
- Immediate Mitigation: Isolate the CGM CLININET system on a strict network segment with firewall rules to limit access to authorized devices and personnel only .
- Monitor Logs: Closely monitor authentication logs for multiple logins from the same certificate number from different source IPs or at unusual times, which could indicate credential sharing or theft.
- Vendor Patch: The only complete fix is a server-side patch from CGM that moves authentication to the server, implementing proper cryptographic verification of the smart card .
- Multi-Factor Authentication (MFA): If supported by the application or via a gateway, implement an additional MFA layer to compensate for the broken smart card logic.
Impact:
Successful exploitation allows an attacker to fully impersonate any legitimate user. In a healthcare setting like CGM CLININET, this leads to unauthorized access to sensitive patient health information (PHI), a direct violation of regulations like HIPAA and GDPR. Attackers could view, modify, or delete medical records, potentially leading to incorrect treatment and patient harm. They could also disrupt clinical workflows, causing operational chaos and denying access to critical systems for healthcare providers .
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Sources:
Reported By: nvd.nist.gov
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