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How the mentioned CVE works:
The vulnerability exists within the file upload validation mechanism of the Vercel AI SDK. The SDK implements a whitelist of allowed file extensions and MIME types to prevent the upload of potentially dangerous files. However, the validation logic can be bypassed by crafting a multipart form-data request with specific inconsistencies. An attacker could supply a filename with a permitted extension (e.g., .txt) while simultaneously setting the Content-Type header to a prohibited MIME type (e.g., application/x-javascript). Due to improper parsing, the SDK might only check the filename, allowing the malicious file with the incorrect MIME type to pass the whitelist. This bypass could enable the upload of scripts or other executable content disguised as a benign file type, depending on how the uploaded files are processed and served by the application using the SDK.
Platform: Vercel AI SDK
Version: < 5.0.52
Vulnerability: File Upload Bypass
Severity: Low
date: 2024-11-07
Prediction: 2024-11-14
What Undercode Say:
`curl -F “[email protected];type=application/x-javascript” -F “filename=report.txt” https://api.example.com/upload`
`if (!allowedMimeTypes.includes(file.mimetype)) { // Bypassed check }`
How Exploit:
Craft multipart request.
Mismatch filename and MIME type.
Upload disguised malicious file.
Protection from this CVE
Upgrade SDK version.
Validate both filename and MIME.
Use strict server-side checks.
Impact:
Arbitrary file upload.
Potential script execution.
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Sources:
Reported By: github.com
Extra Source Hub:
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