WWBN AVideo is an open source video platform. In versions up to and including 29.0, the unauthenticated plugin/Scheduler/downloadICS.php endpoint passes attacker-controlled title, description, and joinURL parameters into Scheduler::downloadICS(), which builds an ICS calendar file via the ICS helper class. ICS::escape_string() (objects/ICS.php:167-169) only escapes , and ; and does NOT neutralize CR/LF, so attacker CRLF bytes inside a property value break out and inject arbitrary ICS lines — including END:VEVENT / BEGIN:VEVENT pairs that add entire attacker-controlled calendar events. Because the malicious .ics file is served from the victim's trusted AVideo origin, this enables high-credibility calendar phishing: forged meetings with attacker-chosen SUMMARY, URL, LOCATION, and DESCRIPTION landing in the victim's calendar after import. Commit 764db592f99e545aa86bb9a4ad664ffd14c38ba5 contains an updated fix.

Affected: Packagist: wwbn/avideo

## Summary

The unauthenticated `plugin/Scheduler/downloadICS.php` endpoint passes attacker-controlled `title`, `description`, and `joinURL` parameters into `Scheduler::downloadICS()`, which builds an ICS calendar file via the `ICS` helper class. `ICS::escape_string()` (`objects/ICS.php:167-169`) only escapes `,` and `;` and does NOT neutralize CR/LF, so attacker CRLF bytes inside a property value break out and inject arbitrary ICS lines — including `END:VEVENT` / `BEGIN:VEVENT` pairs that add entire attacker-controlled calendar events. Because the malicious `.ics` file is served from the victim's trusted AVideo origin, this enables high-credibility calendar phishing: forged meetings with attacker-chosen `SUMMARY`, `URL`, `LOCATION`, and `DESCRIPTION` landing in the victim's calendar after import.

## Details

### Vulnerable code path

**`plugin/Scheduler/downloadICS.php`** — unauthenticated entry point:

```php if(!AVideoPlugin::isEnabledByName('Scheduler')){ forbiddenPage('Scheduler is disabled'); } if(empty($_REQUEST['title'])){ forbiddenPage('Title cannot be empty'); } if(empty($_REQUEST['date_start'])){ forbiddenPage('date_start cannot be empty'); }

Scheduler::downloadICS($_REQUEST['title'], $_REQUEST['date_start'], @$_REQUEST['date_end'], @$_REQUEST['reminder'], @$_REQUEST['joinURL'], @$_REQUEST['description']); ```

There is no session check, no CSRF token, no user-role check — only an empty-check on `title`/`date_start` and a plugin-enabled check.

**`plugin…