EUVD-2025-17346
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
3Description
An improper certificate validation vulnerability has been reported to affect File Station 5. If exploited, the vulnerability could allow remote attackers who have gained user access to compromise the security of the system. We have already fixed the vulnerability in the following versions: File Station 5 5.5.6.4791 and later and later
Analysis
CVE-2025-29885 is an improper certificate validation vulnerability in Synology File Station 5 that allows authenticated remote attackers to compromise system confidentiality, integrity, and availability. The vulnerability affects File Station 5 versions prior to 5.5.6.4791 and requires valid user credentials to exploit. With a CVSS score of 8.8 and a low attack complexity, this represents a significant risk to organizations running vulnerable versions, though exploitation requires prior authentication.
Technical Context
This vulnerability stems from improper X.509 certificate validation (CWE-295), likely affecting TLS/SSL certificate verification mechanisms within File Station 5's communication protocols or API endpoints. The vulnerability suggests that the application fails to properly validate certificate chains, expiration dates, or certificate authority signatures, potentially allowing man-in-the-middle attacks or unauthorized system access after initial authentication. The root cause appears to be in the certificate validation logic used during secure communications, possibly in the underlying HTTP client library, HTTPS implementation, or inter-service communication channels within File Station 5. Affected product: CPE context points to Synology File Station 5 versions before 5.5.6.4791.
Affected Products
Synology File Station 5 (Before 5.5.6.4791)
Remediation
Upgrade File Station 5 to version 5.5.6.4791 or later; priority: Critical; details: Vendors have released patched versions that fix improper certificate validation. Immediate patching is required for all affected installations. Interim Mitigation: Restrict File Station 5 access to trusted networks and users; details: Implement network segmentation to limit exposure to authenticated users. This reduces attack surface while patches are being deployed. Interim Mitigation: Monitor certificate validation failures and authentication anomalies; details: Enable detailed logging for HTTPS/TLS errors and suspicious authentication patterns to detect potential exploitation attempts. Interim Mitigation: Review and minimize user access privileges; details: Since exploitation requires valid user credentials, limit the number of users with File Station 5 access and apply principle of least privilege.
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External POC / Exploit Code
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