WeKan Attachment Storage lists.js applyWipLimit ListWIPBleed access control

A flaw has been found in WeKan up to 8.20. Affected is the function applyWipLimit of the file models/lists.js of the component Attachment Storage Handler. Executing a manipulation can lead to improper access controls. The attack can be executed remotely. Upgrading to version 8.21 is able to address this issue. This patch is called 8c0b4f79d8582932528ec2fdf2a4487c86770fb9. It is recommended to upgrade the affected component.