Apache CloudStack: Domain/account resources limits not honored
Due to multiple time-of-check time-of-use race conditions in the resource count check and increment logic, as well as missing validations, users of the platform are able to exceed the allocation limits configured for their accounts/domains. This can be used by an attacker to degrade the infrastructure's resources and lead to denial of service conditions. Users are recommended to upgrade to Apache CloudStack versions 4.20.3.0 or 4.22.0.1, or later, which fixes this issue.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for help- Published
- May 8, 2026
- Updated
- Jun 17, 2026
- EPSS
- 0.4% · 35th percentile
- CWE
- CWE-367
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Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.3
- CNA · apache
- 6.5
- 1.2 point gap
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| apache | cloudstack | cpe:2.3:a:apache:cloudstack |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- apache cloudstack4.0.0 and later · before 4.20.3.0
- apache cloudstack4.21.0.0 and later · before 4.22.0.1
Versions reported by the vendor
Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.
Apache Software Foundation Apache CloudStack
- 4.0.0 and later · up to and including 4.20.2.0affected · semver
- 4.21.0.0 and later · up to and including 4.22.0.0affected · semver
Same product
apache: all recordsOther highest-scoring records for the same primary product.
- CVE-2012-4501Citrix Cloud.com CloudStack, and Apache CloudStack pre-release, allows remote attackers to make arbitrary API calls by leveraging the system42Plan
- CVE-2022-35741Apache CloudStack SAML Single Sign-On XXE41Plan
- CVE-2016-6813Apache CloudStack 4.1 to 4.8.1.0 and 4.9.0.0 contain an API call designed to allow a user to register for the developer API.41Plan
- CVE-2024-39864Apache CloudStack: Integration API service uses dynamic port when disabled40Plan
- CVE-2024-38346Apache CloudStack: Unauthenticated cluster service port leads to remote execution40Plan
- CVE-2019-17562A buffer overflow vulnerability has been found in the baremetal component of Apache CloudStack.40Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-367 · Time-of-check Time-of-use (TOCTOU) Race ConditionCVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- lists.apache.org/thread/n8mt5b7wkpysstb8w7rr9f02kc5cq2xm
- www.openwall.com/lists/oss-security/2026/05/09/5
Vendor advisories and official records. Exploit/PoC links are deliberately left out.