Executive Summary

[{'type': 'paragraph', 'content': 'CVE-2026-3965 is a remote command execution vulnerability in the whyour qinglong software up to version 2.20.1. It affects the API interface, specifically in the file back/loaders/express.ts. The vulnerability arises because the system fails to properly filter and validate user-supplied parameters, particularly the "command" argument, allowing attackers to inject and execute arbitrary shell commands remotely.'}, {'type': 'paragraph', 'content': 'The root cause is improper input validation and flawed API authentication logic, including a bypass of JWT verification via capitalized API endpoints. This allows unauthorized access to sensitive API routes such as /command-run, where user commands are executed without sanitization.'}, {'type': 'paragraph', 'content': 'A proof-of-concept exploit demonstrates sending a specially crafted PUT request to a capitalized API endpoint to execute commands like "whoami" on the server, confirming the vulnerability.'}, {'type': 'paragraph', 'content': 'The vulnerability is publicly disclosed, has an easy exploitability rating, and can be fixed by upgrading to version 2.20.2, which includes a patch addressing the issue.'}] [2, 3, 5]

Useful 0 Not Useful 0

Impact Analysis

This vulnerability allows remote attackers to execute arbitrary shell commands on the affected qinglong server, potentially gaining server-level permissions.

Exploitation can lead to unauthorized access, data compromise, and further attacks within the internal network, impacting the confidentiality, integrity, and availability of the system.

Because the attack can be launched remotely without local access, it poses a significant risk to systems running vulnerable versions.

Additionally, the vulnerability enables attackers to bypass authentication mechanisms, potentially resetting credentials and taking control of the system.

Mitigation requires upgrading to version 2.20.2, which patches the vulnerability and prevents unauthorized command execution and authentication bypass.

Useful 0 Not Useful 0

Compliance Impact

I don't know

Useful 0 Not Useful 0

Detection Guidance

[{'type': 'paragraph', 'content': "This vulnerability can be detected by attempting to exploit the API interface's `/command-run` endpoint with crafted requests that bypass the input validation and authentication mechanisms."}, {'type': 'paragraph', 'content': 'A proof-of-concept involves sending a PUT request to the endpoint `/apI/system/command-run` (note the capitalized "I" in "apI" which bypasses the regex filter) with a JSON payload containing a command such as "whoami". If the command executes successfully on the server, the system is vulnerable.'}, {'type': 'paragraph', 'content': 'Example command using curl to test the vulnerability:'}, {'type': 'list_item', 'content': 'curl -X PUT http://<target-host>:<port>/apI/system/command-run -H "Content-Type: application/json" -d \'{"command":"whoami"}\''}, {'type': 'paragraph', 'content': 'If the response returns the output of the command (e.g., the username running the service), it indicates the vulnerability is present.'}] [2]

Useful 0 Not Useful 0

Mitigation Strategies

The primary and recommended mitigation step is to upgrade the affected qinglong software to version 2.20.2, which contains the patch that fixes this vulnerability.

The patch addresses the improper input validation and authentication bypass issues in the API interface, preventing unauthorized command execution.

Until the upgrade can be applied, it is advisable to restrict access to the vulnerable API endpoints, especially `/command-run`, by implementing network-level controls such as firewall rules or API gateway filtering to block unauthorized or suspicious requests.

Additionally, monitor logs for unusual API requests, especially those targeting `/command-run` with suspicious payloads.

Useful 0 Not Useful 0