Arbitrary redirect while using certain URLs
We recommend updating to the current version 5.7.7. You can get the update to 5.7.7 regularly via the Auto-Updater or directly via the download overview.
For older versions you can use the Security Plugin:
https://store.shopware.com/en/swag575294366635f/shopware-security-plugin.html
https://docs.shopware.com/en/shopware-5-en/securityupdates/security-update-01-2022