GHSA-p8q3-h652-65vx October CMS safe mode bypass using Twig sandbox escape

• Packagist october/system: >= 3.0.0, < 3.4.15 → fixed in 3.4.15

Impact An authenticated backend user with the `editor.cms_pages`, `editor.cms_layouts`, or `editor.cms_partials` permissions who would normally not be permitted to provide PHP code to be executed by the CMS due to `cms.safe_mode` 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.safe_mode` enabled. Still, it would be a problem for anyone relying on `cms.safe_mode` 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 [email protected]