Impact

A reflected cross-site scripting (XSS) vulnerability exists on the dynamic image URL generator view within the Wagtail admin interface. A user with a limited-permission editor account for the Wagtail admin could craft a URL that, when viewed by a user with higher privileges, could perform actions with that user's credentials. The vulnerability is present for all sites, even if they do not enable the dynamic image serve view. The vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin.

Patches

Patched versions have been released as Wagtail 7.3.3 and 7.4.2.

Workarounds

For sites that cannot easily upgrade to a current supported version, the vulnerability can be patched by adding the following code to urls.py URL pattern declarations to override the vulnerable view. This disables the admin dynamic image preview functionality, while the public-facing dynamic image serve view still works.

python from django.http import HttpResponseBadRequest from django.urls import path from wagtail.admin import urls as wagtailadminurls

def disabledoutput(request, imageid): return HttpResponseBadRequest("", contenttype="text/plain")

urlpatterns = [ # Example where the CMS admin is at /admin/. # Add this before the Wagtail admin URLs registration, with the same sub-path. path("admin/images/<int:imageid>/generateurl/output/", disabledoutput), path("admin/", include(wagtailadminurls)), ]

Acknowledgements

Many thanks to Thibaud Colas (@thibaudcolas) for reporting this issue.

For more information

If you have any questions or comments about this advisory:

- Visit Wagtail's support channels - Email us at security@wagtail.org (view our security policy for more information).

Impact Due to a missing permission check on the image preview endpoint, a user with access to the Wagtail admin can preview any image. The existing data of the image object itself is not exposed. The vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin.

Patches Patched versions have been released as Wagtail 7.0.8, 7.3.3, 7.4.2.

Workarounds For sites that cannot easily upgrade to a current supported version, the vulnerability can be patched by adding the following code to urls.py URL pattern declarations to override the vulnerable view.

python from django.core.exceptions import PermissionDenied from django.shortcuts import getobjector404 from django.urls import path from wagtail.admin import urls as wagtailadminurls from wagtail.images.permissions import permissionpolicy from wagtail.images.views import preview

def patchedpreview(request, imageid, filterspec): image = getobjector404(getimagemodel(), id=imageid)

if not permissionpolicy.userhaspermissionforinstance(request.user, "change", image): raise PermissionDenied

return preview(request, imageid, filterspec)

urlpatterns = [ # Example where the CMS admin is at /admin/. # Add this before the Wagtail admin URLs registration, with the same sub-path. path("admin/images/<int:imageid>/preview/<str:filterspec>/", patchedpreview) path("admin/", include(wagtailadminurls)), ]

Acknowledgements Many thanks to @0x1saac and @harshakshit for reporting this issue.

For more information If you have any questions or comments about this advisory:

Visit Wagtail's support channels Email us at security@wagtail.org (view our security policy for more information).

Impact

An authenticated admin user can trigger expensive rendition processing with purposefully crafted filter specs resulting in potentially service degradation.

The vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin.

Patches Patched versions have been released as Wagtail 7.0.8, 7.3.3, 7.4.2.

Workarounds For sites that cannot easily upgrade to a current supported version, the vulnerability can be patched by adding the following code to urls.py URL pattern declarations to override the vulnerable view.

python from django.core.exceptions import PermissionDenied from django.http import HttpResponseBadRequest from django.shortcuts import getobjector404 from django.urls import path from wagtail.admin import urls as wagtailadminurls from wagtail.images.exceptions import InvalidFilterSpecError from wagtail.images.permissions import permissionpolicy from wagtail.images.views import preview

def patchedpreview(request, imageid, filterspec): image = getobjector404(getimagemodel(), id=imageid)

if not permissionpolicy.userhaspermissionforinstance(request.user, "change", image): raise PermissionDenied

try: filterobj = Filter(spec=filterspec) except InvalidFilterSpecError: return HttpResponseBadRequest("Invalid filter spec", contenttype="text/plain")

allowed = {"original", "width", "height", "min", "max", "fill"} if any(operation.method not in allowed for operation in filterobj.operations): return HttpResponseBadRequest("Invalid filter spec", contenttype="text/plain")

return preview(request, imageid, filterspec)

urlpatterns = [ # Example where the CMS admin is at /admin/. # Add this before the Wagtail admin URLs registration, with the same sub-path. path("admin/images/<int:imageid>/preview/<str:filterspec>/", patchedpreview) path("admin/", include(wagtailadminurls)), ]

Acknowledgements Many thanks to @0x1saac for reporting this issue.

For more information If you have any questions or comments about this advisory:

Visit Wagtail's support channels Email us at security@wagtail.org (view our security policy for more information).

Impact The Documents and Images chooser's chosen endpoint incorrectly listed items for which the user has not been granted choose permission. A user with access to the Wagtail admin could see the filename and name and URLs of documents and images in those collections.

The vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin.

Patches Patched versions have been released as Wagtail 7.0.8, 7.3.3, 7.4.2.

Workarounds N/A

Acknowledgements Many thanks to @harshakshit for reporting this issue.

For more information If you have any questions or comments about this advisory:

Visit Wagtail's support channels Email us at security@wagtail.org (view our security policy for more information).

Impact A low-level user with the "Can submit translation" permission can create translations for any page, including those they do not have permissions for.

Patches Patched versions have been released as Wagtail 7.0.8, 7.3.3, 7.4.2.

Workarounds N/A

Acknowledgements

Many thanks to @devansh3008 and @alanturing881 for reporting this issue.

For more information

If you have any questions or comments about this advisory:

Visit Wagtail's support channels Email us at security@wagtail.org (view our security policy for more information).