check if image is not corrupted during upload (#218)

avatar/forms.py

@@ -5,6 +5,7 @@
 from django.template.defaultfilters import filesizeformat
 from django.utils.safestring import mark_safe
 from django.utils.translation import gettext_lazy as _
+from PIL import Image, ImageOps
 
 from avatar.conf import settings
 from avatar.models import Avatar
@@ -82,6 +83,12 @@ def clean_avatar(self):
                 }
             )
 
+        try:
+            image = Image.open(data)
+            ImageOps.exif_transpose(image)
+        except TypeError:
+            raise forms.ValidationError(_("Corrupted image"))
+
         count = Avatar.objects.filter(user=self.user).count()
         if 1 < settings.AVATAR_MAX_AVATARS_PER_USER <= count:
             error = _(