Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HSummary
CVE-2025-21547 is a critical-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Oracle Hospitality Opera 5. Its CVSS base score is 9.1 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique OS Exhaustion Flood (T1499.001); ranked at the 45th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
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-2025-21547 is a vulnerability in the Opera Servlet component of Oracle Hospitality OPERA 5, which is part of Oracle Hospitality Applications. The supported versions affected by this issue are 5.6.19.20, 5.6.25.8, 5.6.26.6, and 5.6.27.1. It is classified under CWE-400 (Uncontrolled Resource Consumption) and carries a CVSS 3.1 base score of 9.1, with the vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H, emphasizing high impacts on confidentiality and availability.
An unauthenticated attacker with network access via HTTP can easily exploit this vulnerability to compromise Oracle Hospitality OPERA 5. Successful attacks enable unauthorized access to critical data or complete access to all Oracle Hospitality OPERA 5 accessible data, along with the unauthorized ability to cause a hang or frequently repeatable crash, resulting in a complete denial of service.
Mitigation details are provided in the Oracle Critical Patch Update advisory available at https://www.oracle.com/security-alerts/cpujan2025.html, published on 2025-01-21. Security practitioners should consult this advisory for patch information and recommended actions specific to the affected versions.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-2536
Vulnerability Data
Vulnerability in the Oracle Hospitality OPERA 5 product of Oracle Hospitality Applications (component: Opera Servlet). Supported versions that are affected are 5.6.19.20, 5.6.25.8, 5.6.26.6 and 5.6.27.1. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle…
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Hospitality OPERA 5. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Oracle Hospitality OPERA 5 accessible data and unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Hospitality OPERA 5. CVSS 3.1 Base Score 9.1 (Confidentiality and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H).
- 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.