Impact
A user with access to the media manager that stores SVG files could create a stored XSS attack against themselves and any other user with access to the media manager when SVG files are supported.
SVG files are supported by default in v3 for convenience; however, this has resulted in multiple mistaken vulnerability reports from security researchers. As per the documentation, if a backend user is not trusted, the advice is to remove the svg extension from the list of supported file types.
Patches
The issue has been patched in v3.5.2 by including an SVG sanister. It is enabled by default for new installations but must be enabled for existing sites in the config/media.php file.
'cleanvectors' => true,
Workarounds
If you cannot upgrade for this patch, follow the pervious advice and remove svg from the supported file types.
References
- https://github.com/octobercms/october/blob/3.x/config/media.php
Credits to: - Faris Krivic - Okan Kurtulus - Aldin Visnjic - Bug Shankar
For more information If you have any questions or comments about this advisory: Email us at hello@octobercms.com
Impact
An authenticated backend user with the editor.cmspages, editor.cmslayouts, or editor.cmspartials permissions who would normally not be permitted to provide PHP code to be executed by the CMS due to cms.safemode being enabled can craft a special request to include PHP code in the CMS template.
This is not a problem for anyone who trusts their users with those permissions to usually write & manage PHP within the CMS by not having cms.safemode enabled. Still, it would be a problem for anyone relying on cms.safemode to ensure that users with those permissions in production do not have access to write and execute arbitrary PHP.
Patches
This issue has been patched in v3.4.15.
Workarounds
As a workaround, remove the specified permissions from untrusted users.
References
Credits to: - Vasiliy Bodrov
For more information If you have any questions or comments about this advisory: Email us at hello@octobercms.com
Impact
An authenticated backend user with the editor.cmspages, editor.cmslayouts, or editor.cmspartials permissions who would normally not be permitted to provide PHP code to be executed by the CMS due to cms.safemode being enabled can write specific Twig code to escape the Twig sandbox and execute arbitrary PHP.
This is not a problem for anyone who trusts their users with those permissions to usually write and manage PHP within the CMS by not having cms.safemode enabled. Still, it would be a problem for anyone relying on cms.safemode to ensure that users with those permissions in production do not have access to write and execute arbitrary PHP.
Patches
This issue has been patched in v3.4.15.
Workarounds
As a workaround, remove the specified permissions from untrusted users.
References
Credits to: - Vasiliy Bodrov
For more information If you have any questions or comments about this advisory: Email us at hello@octobercms.com