free5GC UDR is the user data repository (UDR) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, the NEF component reliably leaks internal parsing error details (e.g., invalid character n after top-level value) to remote clients, which can aid attackers in service fingerprinting. All deployments of free5GC using the Nnef_PfdManagement service may be affected. free5gc/udr pull request 56 contains a patch for the issue. There is no direct workaround at the application level. The recommendation is to apply the provided patch.
Weakness
The product generates an error message that includes sensitive information about its environment, users, or associated data.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Udr | Free5gc | * | 1.4.1 (including) |
Potential Mitigations
- Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
- If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
- Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/215.html
- https://cwe.mitre.org/data/definitions/463.html
- https://cwe.mitre.org/data/definitions/54.html
- https://cwe.mitre.org/data/definitions/7.html