mastodon/config/imagemagick/policy.xml
Claire dc8f1fbd97
Merge pull request from GHSA-9928-3cp5-93fm
* Fix attachments getting processed despite failing content-type validation

* Add a restrictive ImageMagick security policy tailored for Mastodon

* Fix misdetection of MP3 files with large cover art

* Reject unprocessable audio/video files instead of keeping them unchanged
2023-07-06 15:05:05 +02:00

28 lines
1 KiB
XML

<policymap>
<!-- Set some basic system resource limits -->
<policy domain="resource" name="time" value="60" />
<policy domain="module" rights="none" pattern="URL" />
<policy domain="filter" rights="none" pattern="*" />
<!--
Ideally, we would restrict ImageMagick to only accessing its own
disk-backed pixel cache as well as Mastodon-created Tempfiles.
However, those paths depend on the operating system and environment
variables, so they can only be known at runtime.
Furthermore, those paths are not necessarily shared across Mastodon
processes, so even creating a policy.xml at runtime is impractical.
For the time being, only disable indirect reads.
-->
<policy domain="path" rights="none" pattern="@*" />
<!-- Disallow any coder by default, and only enable ones required by Mastodon -->
<policy domain="coder" rights="none" pattern="*" />
<policy domain="coder" rights="read | write" pattern="{PNG,JPEG,GIF,HEIC,WEBP}" />
<policy domain="coder" rights="write" pattern="{HISTOGRAM,RGB,INFO}" />
</policymap>