[4.0.x] Fixed CVE-2023-24580 -- Prevented DoS with too many uploaded files.

Thanks to Jakob Ackermann for the report.

4 files changed, 46 insertions, 2 deletions

diff --git a/docs/ref/exceptions.txt b/docs/ref/exceptions.txt
index 8e8fe4347a..025b9dab01 100644
--- a/docs/ref/exceptions.txt
+++ b/docs/ref/exceptions.txt
@@ -84,12 +84,17 @@ Django core exception classes are defined in ``django.core.exceptions``.
     * ``SuspiciousMultipartForm``
     * ``SuspiciousSession``
     * ``TooManyFieldsSent``
+    * ``TooManyFilesSent``
 
     If a ``SuspiciousOperation`` exception reaches the ASGI/WSGI handler level
     it is logged at the ``Error`` level and results in
     a :class:`~django.http.HttpResponseBadRequest`. See the :doc:`logging
     documentation </topics/logging/>` for more information.
 
+.. versionchanged:: 3.2.18
+
+    ``SuspiciousOperation`` is raised when too many files are submitted.
+
 ``PermissionDenied``
 --------------------
 
diff --git a/docs/ref/settings.txt b/docs/ref/settings.txt
index 850aa0df21..5571775618 100644
--- a/docs/ref/settings.txt
+++ b/docs/ref/settings.txt
@@ -1076,6 +1076,28 @@ could be used as a denial-of-service attack vector if left unchecked. Since web
 servers don't typically perform deep request inspection, it's not possible to
 perform a similar check at that level.
 
+.. setting:: DATA_UPLOAD_MAX_NUMBER_FILES
+
+``DATA_UPLOAD_MAX_NUMBER_FILES``
+--------------------------------
+
+.. versionadded:: 3.2.18
+
+Default: ``100``
+
+The maximum number of files that may be received via POST in a
+``multipart/form-data`` encoded request before a
+:exc:`~django.core.exceptions.SuspiciousOperation` (``TooManyFiles``) is
+raised. You can set this to ``None`` to disable the check. Applications that
+are expected to receive an unusually large number of file fields should tune
+this setting.
+
+The number of accepted files is correlated to the amount of time and memory
+needed to process the request. Large requests could be used as a
+denial-of-service attack vector if left unchecked. Since web servers don't
+typically perform deep request inspection, it's not possible to perform a
+similar check at that level.
+
 .. setting:: DATABASE_ROUTERS
 
 ``DATABASE_ROUTERS``
@@ -3658,6 +3680,7 @@ HTTP
 ----
 * :setting:`DATA_UPLOAD_MAX_MEMORY_SIZE`
 * :setting:`DATA_UPLOAD_MAX_NUMBER_FIELDS`
+* :setting:`DATA_UPLOAD_MAX_NUMBER_FILES`
 * :setting:`DEFAULT_CHARSET`
 * :setting:`DISALLOWED_USER_AGENTS`
 * :setting:`FORCE_SCRIPT_NAME`
diff --git a/docs/releases/3.2.18.txt b/docs/releases/3.2.18.txt
index 431d04c989..46c0feb51e 100644
--- a/docs/releases/3.2.18.txt
+++ b/docs/releases/3.2.18.txt
@@ -6,4 +6,12 @@ Django 3.2.18 release notes
 
 Django 3.2.18 fixes a security issue with severity "moderate" in 3.2.17.
 
-...
+CVE-2023-24580: Potential denial-of-service vulnerability in file uploads
+=========================================================================
+
+Passing certain inputs to multipart forms could result in too many open files
+or memory exhaustion, and provided a potential vector for a denial-of-service
+attack.
+
+The number of files parts parsed is now limited via the new
+:setting:`DATA_UPLOAD_MAX_NUMBER_FILES` setting.
diff --git a/docs/releases/4.0.10.txt b/docs/releases/4.0.10.txt
index b01f8c5b1b..4d076ab40e 100644
--- a/docs/releases/4.0.10.txt
+++ b/docs/releases/4.0.10.txt
@@ -6,4 +6,12 @@ Django 4.0.10 release notes
 
 Django 4.0.10 fixes a security issue with severity "moderate" in 4.0.9.
 
-...
+CVE-2023-24580: Potential denial-of-service vulnerability in file uploads
+=========================================================================
+
+Passing certain inputs to multipart forms could result in too many open files
+or memory exhaustion, and provided a potential vector for a denial-of-service
+attack.
+
+The number of files parts parsed is now limited via the new
+:setting:`DATA_UPLOAD_MAX_NUMBER_FILES` setting.