HAX CMS PHP allows users to manage their microsite universe with a PHP backend. Prior to version 11.0.3, 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. 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. Version 11.0.3 contains a patch for the issue.

Affected: npm: @haxtheweb/haxcms-nodejs

### 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 s…