CVE-2025-69253 in Free5GC
Summary
by MITRE • 02/24/2026
free5GC is an open-source project for 5th generation (5G) mobile core networks. Versions up to and including 1.4.1 of the User Data Repository are affected by Improper Error Handling with Information Exposure. 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 vulnerable. free5gc/udr pull request 56 contains a patch. No direct workaround is available at the application level. Applying the official patch is recommended.
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Analysis
by VulDB Data Team • 02/24/2026
The CVE-2025-69253 vulnerability affects the free5GC open-source 5G mobile core network implementation, specifically targeting the User Data Repository component within the NEF (Network Exposure Function) service. This vulnerability represents a critical improper error handling flaw that exposes internal system details to remote attackers through malformed request processing. The affected system demonstrates poor security hygiene by revealing detailed parsing error messages that contain internal implementation specifics, creating a significant information disclosure risk that can be exploited for advanced reconnaissance purposes.
The technical flaw manifests when the Nnef_PfdManagement service processes invalid input data, particularly encountering unexpected characters within top-level values during JSON parsing operations. The system fails to sanitize error messages before returning them to remote clients, thereby leaking internal parsing error details such as "invalid character 'n' after top-level value" directly to external parties. This behavior violates fundamental security principles of error handling and demonstrates a lack of proper input validation and sanitization mechanisms. The vulnerability is categorized under CWE-209, which specifically addresses improper error handling that leads to information exposure, making it a clear example of how inadequate error management can compromise system security.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables sophisticated attackers to perform service fingerprinting and gain insights into the underlying system architecture. Attackers can leverage the leaked error details to understand the internal parsing mechanisms, identify potential attack vectors, and refine their exploitation strategies against other components of the free5GC deployment. This information exposure creates a foundation for more advanced attacks, including potential privilege escalation or further exploitation of related vulnerabilities within the 5G core network infrastructure. The risk is particularly elevated given that all deployments using the Nnef_PfdManagement service are potentially vulnerable, making this a widespread concern across free5GC installations.
Security mitigations for this vulnerability require immediate implementation of the official patch referenced in free5gc/udr pull request 56, which addresses the root cause by implementing proper error handling mechanisms that prevent internal parsing details from being exposed to remote clients. Organizations should not rely on application-level workarounds, as the vulnerability stems from fundamental error handling design flaws that require code-level fixes. The recommended approach aligns with ATT&CK technique T1211, which involves manipulating error handling to gain information about the system, making proactive patch management essential. Additionally, system administrators should consider implementing network-level monitoring to detect unusual error message patterns that might indicate exploitation attempts, while also ensuring proper input validation and sanitization processes are in place to prevent similar issues in other components of the 5G core network infrastructure.