Description
ownCloud Guests before 0.12.5 allows unauthenticated user enumeration via the /apps/guests/register/{email}/{token} endpoint. Because of insufficient validation of the supplied token in showPasswordForm, the server responds differently when an e-mail address corresponds to a valid pending guest user rather than a non-existent user.
References
marketplace.owncloud.com/apps/guests
gist.github.com/...rtshadow/64ae0449e909174d0479a4f23657147f
