Add security release notes

Author: hugovk

docs/releasenotes/8.2.0.rst

@@ -48,7 +48,7 @@ These changes only affect :py:meth:`~PIL.Image.Image.getexif`, introduced in Pil
 Image._MODEINFO
 ^^^^^^^^^^^^^^^
 
-This internal dictionary has been deprecated by a comment since PIL, and is now
+This internal dictionary had been deprecated by a comment since PIL, and is now
 removed. Instead, ``Image.getmodebase()``, ``Image.getmodetype()``,
 ``Image.getmodebandnames()``, ``Image.getmodebands()`` or ``ImageMode.getmode()``
 can be used.
@@ -129,7 +129,56 @@ For example::
 Security
 ========
 
-TODO
+These were all found with `OSS-Fuzz`_.
+
+:cve:`CVE-2021-25287`, :cve:`CVE-2021-25288`: Fix OOB read in Jpeg2KDecode
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+* For J2k images with multiple bands, it's legal to have different widths for each band,
+  e.g. 1 byte for ``L``, 4 bytes for ``A``.
+* This dates to Pillow 2.4.0.
+
+:cve:`CVE-2021-28675`: Fix DOS in PsdImagePlugin
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+* :py:class:`.PsdImagePlugin.PsdImageFile` did not sanity check the number of input
+  layers with regard to the size of the data block, this could lead to a
+  denial-of-service on :py:meth:`~PIL.Image.open` prior to
+  :py:meth:`~PIL.Image.Image.load`.
+* This dates to the PIL fork.
+
+:cve:`CVE-2021-28676`: Fix FLI DOS
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+* ``FliDecode.c`` did not properly check that the block advance was non-zero,
+  potentially leading to an infinite loop on load.
+* This dates to the PIL fork.
+
+:cve:`CVE-2021-28677`: Fix EPS DOS on _open
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+* The readline used in EPS has to deal with any combination of ``\r`` and ``\n`` as line
+  endings. It accidentally used a quadratic method of accumulating lines while looking
+  for a line ending.
+* A malicious EPS file could use this to perform a denial-of-service of Pillow in the
+  open phase, before an image was accepted for opening.
+* This dates to the PIL fork.
+
+:cve:`CVE-2021-28678`: Fix BLP DOS
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+* ``BlpImagePlugin`` did not properly check that reads after jumping to file offsets
+  returned data. This could lead to a denial-of-service where the decoder could be run a
+  large number of times on empty data.
+* This dates to Pillow 5.1.0.
+
+Fix memory DOS in ImageFont
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+* A corrupt or specially crafted TTF font could have font metrics that lead to
+  unreasonably large sizes when rendering text in font. ``ImageFont.py`` did not check
+  the image size before allocating memory for it.
+* This dates to the PIL fork.
 
 Other Changes
 =============
@@ -178,3 +227,4 @@ ImageMagick_ installed.  If both are installed, the tests prefer ImageMagick.
 
 .. _GraphicsMagick: http://www.graphicsmagick.org/
 .. _ImageMagick: https://imagemagick.org/
+.. _OSS-Fuzz: https://github.com/google/oss-fuzz