[security vulnerability] Cross-Site Scripting (XSS) vulnerabilities

[GatekeeperBuster]

Recently, our team found a reflected cross-site scripting (XSS) vulnerability
The vulnerability logic is present in the file:
https://github.com/LibreHealthIO/lh-ehr/blob/master/interface/billing/get_claim_file.php#L25

The echo directly outputs the parameter $_GET['key'] without any sanitization. This makes it susceptible to Cross-Site Scripting (XSS) attacks. As a result, attackers can exploit this vulnerability by injecting malicious html code with $_GET['key']

To fix this vulnerability, we recommend that developers implement properly sanitize (e.g., htmlspecialchars()) for user input before displaying it on the webpage.