If you missed this Catastrophic severity 1 vulnerability, check the temporary solution below, if you do not want to upgrade your software to a not properly tested software. There are currently, at the time of writing, no software upgrade solution available to the whole 3560 series switches.
Cisco Bug 76186 description (requires login)
In dept description:
If you do not use Smart Install, will it prevent the vulnerability if Smart Install is disabled?
Hopefully there will be some proper software upgrades available soon.