CVE-2021-27394
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA vulnerability has been identified in Mendix Applications using Mendix 7 (All versions < V7.23.19), Mendix Applications using Mendix 8 (All versions < V8.17.0), Mendix Applications using Mendix 8 (V8.12) (All versions < V8.12.5), Mendix Applications using Mendix 8 (V8.6) (All versions < V8.6.9), Mendix Applications using Mendix 9 (All versions < V9.0.5). Authenticated, non-administrative users could modify their privileges by manipulating the user role under certain circumstances, allowing them to gain administrative privileges.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidencePrivilege escalation vulnerability in Mendix applications where authenticated non-administrative users can manipulate their user role to gain administrative privileges by exploiting insufficient authorization checks in role management.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 7.0.2, < 7.23.19>= 8.0.0, < 8.17.0>= 9.0.0, < 9.0.5>= 8.6.0, < 8.6.9>= 8.12.0, < 8.12.5CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the Mendix runtime versionLocate the Mendix version in the application's deployment configuration, model metadata, or runtime environment. In Mendix Cloud, check the environment details in the Developer Portal. For on-premise deployments, check the Mendix runtime version file or the model version information exported from Studio Pro.Affected if The installed version falls within any of these ranges: 7.0.2 to 7.23.18, 8.0.0 to 8.16.x, 8.6.0 to 8.6.8, 8.12.0 to 8.12.4, or 9.0.0 to 9.0.4.
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Confirm Mendix built-in security is in useVerify that the application uses Mendix's default role-based security model. This is configured in the Mendix Studio Pro under 'Project Settings' > 'Security', or check the model security settings. The vulnerability exists in the default authorization mechanism for role management.Affected if The application uses Mendix's default security module without custom external authorization layer.
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Verify non-administrative user roles existReview the application's user role definitions in the Mendix model. Check the defined module roles and their assignments to user roles in the security settings. Look for any user-accessible roles that are not marked as administrator.Affected if The application defines non-administrative user roles that can be assigned to regular authenticated users through the application.
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Confirm user self-service role modification is enabledCheck if the application exposes any functionality allowing users to view or modify their own role assignments. This is typically found in the administration module or custom pages that interact with user management microflows.Affected if Users can access role management features or modify their own user role through application interfaces without proper administrative-only access controls.
Your environment is affected if the installed Mendix version is within the affected ranges and the application uses Mendix's default role-based security with non-administrative user roles accessible through application interfaces.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped7.23.198.6.98.12.5
Upgrade Mendix to version 7.23.19, 8.17.0, 8.12.5, 8.6.9, or 9.0.5 (or later) depending on the major version branch in use.
Mendix 7: upgrade to >=7.23.19; Mendix 8: upgrade to >=8.17.0 (or >=8.12.5 for 8.12 line, >=8.6.9 for 8.6 line); Mendix 9: upgrade to >=9.0.5
- 1. Identify your current Mendix version line (7.x, 8.x, or 9.x) in your project settings or deployment configuration.
- 2. For Mendix 7.x applications: Upgrade to version 7.23.19 or later.
- 3. For Mendix 8.x applications: Upgrade to version 8.17.0 or later (if on 8.6.x line, minimum 8.6.9; if on 8.12.x line, minimum 8.12.5).
- 4. For Mendix 9.x applications: Upgrade to version 9.0.5 or later.
- 5. Export your project from the Mendix Studio Pro and open it in the new version to trigger automatic migration.
- 6. Test user role assignments and privilege modifications in a non-production environment to verify the vulnerability is remediated.
- 7. Deploy the upgraded application to production.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation8.0 h
- Implementation16.0 h
- Testing16.0 h
- Review / QA8.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-27394 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-27394 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data