WWBN AVideo is an open source video platform. In versions up to and including 26.0, the restreamer endpoint constructs a log file path by embedding user-controlled `users_id` and `liveTransmitionHistory_id` values from the JSON request body without any sanitization. This log file path is then concatenated directly into shell commands passed to `exec()`, allowing an authenticated user to achieve arbitrary command execution on the server via shell metacharacters such as `$()` or backticks. Commit 99b865413172045fef6a98b5e9bfc7b24da11678 contains a patch.

Affected: Packagist: wwbn/avideo

## Summary

The restreamer endpoint constructs a log file path by embedding user-controlled `users_id` and `liveTransmitionHistory_id` values from the JSON request body without any sanitization. This log file path is then concatenated directly into shell commands passed to `exec()`, allowing an authenticated user to achieve arbitrary command execution on the server via shell metacharacters such as `$()` or backticks.

## Details

The vulnerability exists in `plugin/Live/standAloneFiles/restreamer.json.php`. The data flow is:

**1. User input ingestion** (line 220): ```php $request = file_get_contents("php://input"); $robj = json_decode($request); ```

**2. Log file template** (line 58): ```php $logFile = $logFileLocation . "ffmpeg_restreamer_{users_id}_" . date("Y-m-d-h-i-s") . ".log"; ```

**3. `users_id` injected without sanitization** (line 318): ```php $obj->logFile = str_replace('{users_id}', $robj->users_id, $logFile); ```

**4. `liveTransmitionHistory_id` injected without sanitization** (line 407): ```php $pid[] = startRestream($m3u8, [$value], str_replace(".log", "_{$key}_{$robj->liveTransmitionHistory_id}_{$host}.log", $logFile), $robj); ```

Note: `intval()` is applied to `liveTransmitionHistory_id` in the separate `getProcess()` function (line 805), but NOT in the `runRestream()` path that constructs the log file.

**5. Unsanitized log file path passed to `exec()`** (lines 720, 723): ```php // Line 720 (remote ffmpeg path): execFFMPEGAsyncOrRemote($command . ' > '…