CVE-2023-50019 in Open5GS
Summary
by MITRE • 01/03/2024
An issue was discovered in open5gs v2.6.6. InitialUEMessage, Registration request sent at a specific time can crash AMF due to incorrect error handling of Nudm_UECM_Registration response.
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Analysis
by VulDB Data Team • 05/08/2024
The vulnerability identified as CVE-2023-50019 resides within the open5gs v2.6.6 telecommunications software stack, specifically affecting the Access and Mobility Management Function component. This issue represents a critical flaw in the handling of user equipment registration processes within 5G core networks, where the AMF fails to properly manage error conditions during the Nudm_UECM_Registration procedure. The vulnerability manifests when a specific timing sequence of InitialUEMessage and Registration request triggers an improper error handling mechanism that ultimately leads to system crash.
The technical root cause of this vulnerability stems from inadequate error state management within the AMF's processing of UECM registration responses from the Nudm service. When the registration request arrives at a particular temporal window, the system's error handling logic fails to properly validate or sanitize the incoming Nudm_UECM_Registration response, causing a cascade of failures that results in the AMF process termination. This behavior aligns with CWE-248, an unspecified error in the code execution path that leads to an unexpected program state, and represents a classic example of improper exception handling in telecommunications infrastructure components. The flaw operates at the application layer of the 5G core network architecture, specifically targeting the interface between the AMF and the Nudm service within the open5gs framework.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be exploited to create denial-of-service conditions within 5G networks that rely on open5gs implementations. Attackers can potentially orchestrate coordinated timing attacks to repeatedly trigger the crash condition, effectively rendering the AMF unavailable for legitimate user registration requests. This vulnerability directly impacts the availability and reliability of 5G network services, particularly affecting network slicing and mobile edge computing deployments that depend on stable AMF operations. The exploitability of this condition is enhanced by the fact that it requires only specific timing coordination rather than complex attack vectors, making it a significant concern for network operators deploying open5gs v2.6.6 in production environments.
Mitigation strategies for CVE-2023-50019 should prioritize immediate deployment of the vendor-provided patch or upgrade to a patched version of open5gs software. Network operators should implement monitoring solutions that can detect anomalous registration request patterns that may indicate exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1499.004 for Network Denial of Service, as the exploitation directly impacts network availability. Organizations should also consider implementing rate limiting and temporal request validation mechanisms at the AMF boundary to prevent exploitation through timing-based attacks. Additionally, network segmentation and redundant AMF configurations can help maintain service availability while patches are deployed. Security teams should conduct thorough testing of patched environments to ensure that the fix does not introduce regressions in legitimate user registration workflows, particularly for emergency services and critical communications applications that rely on 5G network availability.