51l3nc3, member of the AXIS OS Bug Bounty Program, has found that the VAPIX API managedoverlayimages.cgi was vulnerable to a race condition attack allowing for an attacker to block access to the overlay configuration page in the web interface of the Axis device. This flaw can only be exploited after authenticating with an operator- or administrator-privileged service account. Axis has released patched AXIS OS versions for the highlighted flaw. Please refer to the Axis security advisory for more information and solution.