Unauthenticated file upload via provider query bypass
Published Sep 1, 2026 · Updated Sep 3, 2026
Missing authentication in Casdoor 4.0 upload-resource API allows remote attackers to upload arbitrary files to configured storage. The anonymous POST policy admits the request, while GetProviderFromContext returns a named provider before RequireSignedIn and UploadResource writes attacker-controlled content and metadata. Exploitation requires a discoverable configured provider and permits storage writes and false attribution; public retrieval additionally depends on provider exposure.
Summary
What happened
Missing authentication in Casdoor 4.0 upload-resource API allows remote attackers to upload arbitrary files to configured storage. The anonymous POST policy admits the request, while GetProviderFromContext returns a named provider before RequireSignedIn and UploadResource writes attacker-controlled content and metadata. Exploitation requires a discoverable configured provider and permits storage writes and false attribution; public retrieval additionally depends on provider exposure.
The record
- CVE
- CVE-2026-84423
- Published
- Sep 1, 2026
- Updated
- Sep 3, 2026
- Vendor
- Casdoor
- Product
- Casdoor
- Classifications
- CWE-306, CWE-287, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 1, 2026CVE publishedPublication date reported by the CVE source.
- Sep 3, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=4.0
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Unauthenticated upload-resource proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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