Free5GC up to 1.4.1 UDM Nudm_UECM ueId information disclosure

Summaryinfo

A vulnerability was found in Free5GC up to 1.4.1. It has been classified as problematic. Affected by this issue is the function Nudm_UECM of the component UDM. The manipulation of the argument ueId leads to information disclosure. This vulnerability is listed as CVE-2025-69251. The attack may be initiated remotely. There is no available exploit. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability was found in Free5GC up to 1.4.1 and classified as problematic. This issue affects the function Nudm_UECM of the component UDM. The manipulation of the argument ueId with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality. The summary by CVE is:

free5gc UDM provides Unified Data Management (UDM) for free5GC, an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, remote attackers can inject control characters (e.g., %00) into the ueId parameter, triggering internal URL parsing errors (net/url: invalid control character). This exposes system implementation details and can aid in service fingerprinting. All deployments of free5GC using the UDM Nudm_UECM service may be affected. free5gc/udm pull request 76 contains a fix for the issue. No direct workaround is available at the application level. Applying the official patch is recommended.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2025-69251 since 12/30/2025. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1592 for this issue.

Applying the patch 504b14458d156558b3c0ade7107b86b3d5e72998 is able to eliminate this problem. The bugfix is ready for download at github.com.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• Free5GC

Version

• 1.4.0
• 1.4.1

License

• open-source

Website

• Product: https://github.com/free5gc/free5gc/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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