Executive Summary

CVE-2026-3797 is a security vulnerability in Tiandy Video Surveillance System version 7.17.0, specifically in the uploadFile function of the CLS_REST_File.java source file.

The vulnerability occurs because the system does not properly validate the fileName argument, allowing an attacker to upload files without restriction.

This unrestricted file upload can include dangerous file types such as .jsp, .jspx, .exe, and .sh, which may be automatically processed by the system.

If the upload directory is web-accessible and the server executes scripts in that directory, an attacker can upload a malicious webshell and execute code remotely.

The vulnerability can be exploited remotely without authentication, and a proof-of-concept exploit is publicly available.

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Impact Analysis

This vulnerability can impact you by allowing attackers to upload malicious files to your system, potentially leading to unauthorized remote code execution.

Such an attack can compromise the confidentiality, integrity, and availability of your video surveillance system.

If exploited, attackers could gain control over the system, execute arbitrary commands, and disrupt normal operations.

Because the exploit requires no authentication and can be initiated remotely, it poses a significant security risk.

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Compliance Impact

I don't know

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Detection Guidance

[{'type': 'paragraph', 'content': 'This vulnerability can be detected by checking if the Tiandy Video Surveillance System version 7.17.0 is running and if the uploadFile function allows unrestricted file uploads without validating file extensions.'}, {'type': 'paragraph', 'content': 'One practical detection method is to attempt uploading files with various extensions (e.g., .jsp, .jspx, .exe, .sh) to the upload endpoint and observe if the files are accepted and accessible.'}, {'type': 'paragraph', 'content': 'If the upload directory is web-accessible, you can try accessing the uploaded files via a URL to verify if they execute, indicating the vulnerability.'}, {'type': 'paragraph', 'content': 'Commands to assist detection might include using curl or wget to upload test files and then using curl or a browser to access them. For example:'}, {'type': 'list_item', 'content': 'curl -F "[email protected]" http://target-ip-or-domain/path/to/upload'}, {'type': 'list_item', 'content': 'curl http://target-ip-or-domain/path/to/uploaded/test.jsp'}, {'type': 'paragraph', 'content': 'Additionally, network monitoring tools can be used to detect unusual file upload activity to the affected endpoint.'}] [2, 3]

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Mitigation Strategies

Currently, no official mitigations or patches have been provided by the vendor for this vulnerability.

Immediate steps include restricting or disabling the file upload functionality if possible, especially the uploadFile function in the affected version.

Ensure that the upload directory (configured by CLS_Easy7_Types.file_path) is not web-accessible or does not allow execution of uploaded files, for example by removing execute permissions or placing it outside the web root.

Consider network-level protections such as blocking or monitoring HTTP requests to the upload endpoint to detect or prevent malicious uploads.

Ultimately, consider replacing or upgrading the affected product to a more secure alternative, as no vendor response or patch is available.

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