Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2024-56921 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Open5Gs Open5Gs. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique OS Exhaustion Flood (T1499.001); ranked at the 39th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SC-5 (Denial-of-service Protection) and SC-6 (Resource Availability) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2024-56921 is a denial-of-service vulnerability in Open5GS version 2.7.2, affecting the AMF (Access and Mobility Management Function) component. The issue stems from incorrect error handling in the gmm_state_exception() function when processing a Nausf_UEAuthentication_Authenticate response. Specifically, an InitialUEMessage or Registration request sent at a precise timing can trigger this flaw, causing the AMF to crash. The vulnerability is rated with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) and is associated with CWE-400 (Uncontrolled Resource Consumption).
The vulnerability can be exploited remotely over the network by unauthenticated attackers with no privileges or user interaction required. An attacker simply needs to send a crafted Registration request or InitialUEMessage at the exact moment when the AMF is expecting the authentication response, leading to an unhandled exception and process crash. Successful exploitation results in high-impact availability disruption, potentially denying service to legitimate UEs attempting to register on the 5G network.
Mitigation is available through a patch in Open5GS, as detailed in the commit at https://github.com/open5gs/open5gs/commit/f780f9af45c27b6f49987d96ba71dedb3dd85840. Additional details on the issue, including reproduction steps and discussion, are provided in the GitHub issue tracker at https://github.com/open5gs/open5gs/issues/3608. Security practitioners should update to a patched version of Open5GS beyond v2.7.2 to address this flaw.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-53450
Vulnerability Data
An issue was discovered in Open5gs v2.7.2. InitialUEMessage, Registration request sent at a specific time can crash AMF due to incorrect error handling of gmm_state_exception() function upon receipt of the Nausf_UEAuthentication_Authenticate response.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
SC-5 directly limits the effects of resource-exhaustion events that constitute uncontrolled consumption.
SC-6 enforces explicit allocation limits on resources, structurally preventing the weakness from occurring.
Process isolation confines resource consumption to separate domains, reducing blast radius without stopping the root flaw.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Explicitly requires monitoring and maintaining resource capacity, directly addressing uncontrolled consumption to preserve availability.
Continuous monitoring of computing resources can detect resource exhaustion but does not itself enforce allocation limits.
Resilience mechanisms such as avoiding single points of failure indirectly reduce impact of resource exhaustion.
Hardened configuration baselines can include resource quotas and limits that constrain consumption.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Resource-utilization monitoring and alerting on bottlenecks or overloads limits the impact of denial-of-service or resource-exhaustion attacks.
By continuously monitoring utilization, stress-testing peak loads, and maintaining documented plans to scale or throttle resources, the control directly limits an attacker’s ability to drive a system into uncontrolled resource exhaustion.
Pre-agreed severity-based prioritization and resource allocation during incident triage reduce the likelihood that an attacker-induced resource exhaustion will overwhelm the organization before corrective action is taken.
Business-continuity plans that include resource-management controls reduce the likelihood that an attacker can trigger uncontrolled resource consumption by forcing the system into a degraded or fallback state.
Defining RTOs and capacity requirements for ICT services during business-impact analysis forces organizations to provision sufficient resources and throttling mechanisms, reducing the likelihood that an attacker can induce denial-of-service through uncontrolled resource consumption.
Early notification of anomalous resource consumption or system malfunctions enables throttling or isolation before availability is lost.