Mac OS 9 Open Transport Malformed ICMP Datagram Response DoS
Remote / Network Access
Denial of Service
Loss of Availability
Open Transport in Mac OS 9 contains a flaw that may allow a remote denial of service. The issue is triggered when sending a malformed 29 byte long UDP packet, which will cause the machine to respond with an 1,500 byte long ICMP packet. It is possible for a remote attacker to use this behavior as an amplifier against other targets.
Upgrade to Open Transport version 2.6 or higher, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.