Cisco IOS contains a flaw that may allow a remote denial of service. The issue is triggered when refreshing the SSL VPN portal page via a clientless SSL VPN. This may allow a remote attacker to cause a loss of availability for the device.
Remote / Network Access
Loss of Availability
Upgrade to version 15.1(2)T5 or higher, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.