Description

Casdoor through 4.4.0 fails to properly mask the instance-wide built-in certificate private key in /api/get-certs and /api/get-cert endpoints, allowing organization administrators to retrieve it. Attackers can use the exposed private key to forge JWT tokens for any user in any organization, including global administrators.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.6",
  "pubDate": "2026-09-14T18:20:28.720Z",
  "pubdate": "2026-09-14T18:20:28.720Z",
  "executiveSummary": "Casdoor versions through 4.4.0 contain a critical information disclosure vulnerability within the API layer, specifically affecting the /api/get-certs and /api/get-cert endpoints.\nThe vulnerability originates from a failure to properly sanitize and mask instance-wide built-in certificate private keys during API responses.\nThis flaw allows authenticated users with organization administrator privileges to gain unauthorized access to cryptographic material that should be restricted to system-level administrators.\nBy retrieving the private key, an attacker can bypass standard authentication mechanisms by forging JSON Web Tokens (JWT) for any user within the Casdoor instance.\nThe impact is comprehensive, enabling complete account takeover, including global administrator profiles, which effectively grants the attacker full control over the identity management infrastructure.\nExploitation requires active authenticated access to an organization administrator account, after which the attacker can interact with the vulnerable API endpoints to extract the sensitive key data.\nThe risk is classified as critical due to the potential for total system compromise and the violation of fundamental authentication integrity.",
  "technicalDetails": "The vulnerability resides within the API response handling logic for the /api/get-certs and /api/get-cert endpoints in Casdoor versions up to 4.4.0. These endpoints are intended to manage organizational certificate metadata, but they perform inadequate filtering when serializing certificate data for return to the client.\nThe root cause is an improper implementation of access control and data redaction at the object level. Specifically, the application logic does not distinguish between public certificate information and the highly sensitive private key material associated with the instance-wide built-in certificate. Consequently, the private key is included in the JSON response payload sent to the authenticated user.\nAn attacker possessing organization administrator privileges can trigger this vulnerability by sending a GET request to either /api/get-certs or /api/get-cert. Upon receiving the response, the attacker parses the JSON object to locate the private key field. Once obtained, the private key provides the cryptographic material necessary to sign arbitrary JWTs.\nThe attack flow follows these steps: 1) The attacker authenticates as an organization administrator. 2) The attacker invokes the /api/get-certs or /api/get-cert API endpoint. 3) The server returns a serialized object containing the private key. 4) The attacker extracts the key and uses it locally to sign a malicious JWT payload. 5) By setting the 'sub' and 'claims' fields of the forged JWT to represent a global administrator account, the attacker can present this token to the Casdoor authentication middleware.\nSince the JWT is signed with the legitimate instance-wide private key, the system validates the forged token as authentic. This allows the attacker to achieve post-exploitation objectives, such as modifying global configuration, deleting user data, or creating backdoored accounts with administrative privileges, effectively bypassing all organizational boundaries and security controls within the Casdoor instance."
}