CVE-2025-69208 affects the free5GC User Data Repository (UDR), a critical component of the open-source 5G core network implementation. The vulnerability is classified under CWE-209, which involves the generation of error messages containing sensitive information. Specifically, in versions of free5GC prior to 1.4.1, the Nnef_PfdManagement service improperly handles parsing errors by returning detailed error messages to remote clients. For example, if an invalid character such as 'n' appears after a top-level value during parsing, the server responds with an error message that reveals internal processing details. This behavior can be exploited by attackers to fingerprint the server software version and gain insights into the internal logic and data structures, potentially facilitating more targeted attacks. The vulnerability does not require authentication or user interaction and can be triggered remotely over the network. Although the CVSS 4.0 score is low (2.7), reflecting limited direct impact on confidentiality, integrity, or availability, the information leakage could be leveraged in multi-stage attacks. The issue is resolved in free5GC version 1.4.1 by correcting error handling to avoid exposing sensitive internal details. No direct application-level workarounds exist, making patching the primary mitigation strategy. There are no known exploits in the wild as of the publication date.

The primary impact of CVE-2025-69208 is information disclosure through detailed error messages. While the vulnerability does not directly compromise confidentiality, integrity, or availability, the leaked information can assist attackers in fingerprinting the free5GC UDR component and understanding its internal logic. This reconnaissance capability can facilitate subsequent attacks, such as crafting targeted exploits or bypassing security controls. For organizations deploying free5GC as part of their 5G core infrastructure, this vulnerability could increase the risk profile of their network by providing attackers with valuable intelligence. Given the critical role of UDR in managing subscriber data and policies, any compromise or targeted attack enabled by such reconnaissance could have serious downstream effects. However, the low CVSS score and absence of known exploits suggest the immediate risk is limited. Still, the strategic importance of 5G core networks globally means that even low-severity vulnerabilities warrant prompt remediation to maintain robust security postures.

The definitive mitigation for CVE-2025-69208 is to upgrade the free5GC UDR component to version 1.4.1 or later, where the improper error handling has been fixed. Organizations should implement a patch management process that prioritizes this update, especially in production 5G core environments. Since no direct application-level workarounds exist, network-level controls can provide temporary risk reduction: for example, restricting access to the Nnef_PfdManagement service to trusted management networks or using application-layer firewalls to filter malformed requests that trigger parsing errors. Additionally, monitoring and logging should be enhanced to detect unusual or repeated error-triggering requests that may indicate reconnaissance attempts. Security teams should also review error handling configurations and ensure that verbose error messages are disabled or sanitized in all network-facing services. Finally, integrating this vulnerability into vulnerability management and incident response workflows will help maintain ongoing awareness and readiness.