CVE-2026-71262
Received Received - Intake

IoTSharp BlobStorageController Path Traversal Vulnerability

Publication date: 2026-08-05

Last updated on: 2026-08-05

Assigner: 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c

Description
IoTSharp BlobStorageController.cs lacks the [Authorize] attribute applied to every other controller in the application (DevicesController, CustomersController, TenantsController, etc.), and no global authorization FallbackPolicy is configured in Startup.cs, leaving its Upload/Download/List/Modify/Delete endpoints reachable by unauthenticated remote attackers. The path/filename parameters passed to these endpoints (e.g. `_blob.WriteFileAsync($"{path}/{formFile.FileName}", ...)`) are used without sanitization, enabling path traversal that allows writing, reading, modifying, and deleting arbitrary files outside the intended blob storage directory, including web-accessible paths that can be leveraged for remote code execution via webshell upload.

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Meta Information

Published
2026-08-05
Last Modified
2026-08-05
Generated
2026-08-05
AI Q&A
2026-08-05
EPSS Evaluated
N/A
NVD
CVE-2026-71262
EUVD
EUVD-2026-53347

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
iotsharp iotsharp *

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-306 The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

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Executive Summary

This vulnerability is in IoTSharp's BlobStorageController.cs where the [Authorize] attribute is missing on its endpoints. Other controllers like DevicesController have this attribute, but BlobStorageController does not. Additionally, there is no global authorization fallback policy configured in Startup.cs. This leaves the Upload, Download, List, Modify, and Delete endpoints accessible to unauthenticated remote attackers.

Detection Guidance

Check if the BlobStorageController.cs endpoints are accessible without authentication by sending requests to Upload/Download/List/Modify/Delete endpoints. Test for path traversal by using sequences like ../ in path/filename parameters to attempt accessing files outside the intended directory.

Impact Analysis

Unauthenticated attackers can exploit this to perform path traversal attacks. They can write, read, modify, or delete arbitrary files outside the intended blob storage directory. If web-accessible paths are targeted, attackers could upload webshells to achieve remote code execution on the server.

Compliance Impact

This vulnerability could lead to unauthorized access and modification of sensitive data, violating confidentiality and integrity requirements in GDPR and HIPAA. Unauthorized file access may result in data breaches, triggering regulatory fines and compliance violations.

Mitigation Strategies

Apply the [Authorize] attribute to BlobStorageController.cs and configure a global authorization FallbackPolicy in Startup.cs. Sanitize path/filename parameters to prevent path traversal. Restrict file uploads to specific directories and validate file types.

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