The WooCommerce Help Scout WordPress plugin before 2.9.1 (https://woocommerce.com/products/woocommerce-help-scout/) allows unauthenticated users to upload any files to the site which by default will end up in wp-content/uploads/hstmp.
[
{
"product": "WooCommerce Help Scout",
"vendor": "Unknown",
"versions": [
{
"lessThan": "2.9.1",
"status": "affected",
"version": "2.9.1",
"versionType": "custom"
}
]
}
]