Oracle Hospitality OPERA 5: Uncontrolled Resource Consumption
CVE-2025-21547 is a critical-severity uncontrolled resource consumption vulnerability in Oracle Hospitality OPERA 5 from Oracle, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Oracle Hospitality OPERA 5 versions: 5.6.19.20; 5.6.25.8; 5.6.26.6, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.61% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Oracle Hospitality OPERA 5 you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on oracle.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Oracle | Oracle Hospitality OPERA 5 | 5.6.19.20; 5.6.25.8; 5.6.26.6; 5.6.27.1 | Not stated |
| Oracle | Hospitality Opera 5 | 5.6.19.20; 5.6.25.8; 5.6.26.6; 5.6.27.1 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H. Scored by CNA (oracle.com).
Official description
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 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).
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Uncontrolled Resource Consumption
The product does not properly control the allocation and maintenance of a limited resource.
How developers prevent this class of flaw
- Ensure that protocols have specific limits of scale placed on them.
- Ensure that all failures in resource allocation place the system into a safe posture.
More Uncontrolled Resource Consumption vulnerabilities (CWE-400)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Recent Uncontrolled Resource Consumption vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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