Paymenter vulnerable to Remote Code Execution via public file uploads

Impact

The ticket attachments functionality in Paymenter allows a malicious authenticated user to upload arbitrary files.

With the ability to execute arbitrary code, this vulnerability can be exploited in numerous ways, including but not limited to:

• Extracting sensitive data from the database (e.g. customer information).
• Reading credentials from .env or other configuration files.
• Running arbitrary system commands under the web server user context.

This issue is Critical as it allows a low-privilege authenticated user to fully compromise the application and underlying server.

Patches

This vulnerability was patched by https://github.com/Paymenter/Paymenter/commit/87c3db42282ada1e3cda54b9a01f846926c0669b and was released under the v1.2.11 tag without any other code modifications compared to v1.2.10.

Work arounds

If upgrading is not immediately possible, administrators can mitigate this vulnerability with one or more of the following measures:

• Updating nginx config to download attachments instead of executing them:

location ^~ /storage/ {
    types { }
    default_type application/octet-stream;
    add_header X-Content-Type-Options nosniff;
    try_files $uri =404;
}

• Disallow access to /storage/ fully using a WAF such as Cloudflare

These workarounds significantly reduce risk, but the only guaranteed resolution is upgrading to v1.2.11 or later.