The application image file upload allowed authenticated users to upload
malious .html files. Opening such a file like
https://push.gotify.net/image/ViaxrjzNowdgL-xnEfVV-Ggv5.html
would allow the attacker to execute client side scripts.
The application image upload will now only allow the upload of files
with the following extensions: .gif, .png, .jpg and .jpeg.
Can be enabled via the registration config flag. (disabled per default)
Fixesgotify/server#395
Co-authored-by: pigpig <pigpig@pig.pig>
Co-authored-by: Karmanyaah Malhotra <32671690+karmanyaahm@users.noreply.github.com>
Co-authored-by: Jannis Mattheis <contact@jmattheis.de>