IBM released an advisory in February for a Denial of Service (DoS) vulnerability in AIX versions 5.3, 6.1, and 7.1. The warning seems to have flown under the radar since so far, many companies running the effected AIX OS platforms for their SAP environments have yet to deploy the patch. The vulnerability relates to a flaw in ICMP packet handling. An ICMP echo reply with ID=1 can lead to a DoS. ICMP is part of the Internet Protocol Suite and can be used to relay query messages. Echo reply is a ping utility that can be executed remotely with no authentication and very little complexity. The vulnerability has a CVSS base score of 7.8 and exploitability sub-score of 10 which means it is rated as extremely dangerous. The relevant security update can be downloaded directly from IBM through ftp://aix.software.ibm.com/aix/efixes/security/icmp_fix.tar. Technical information is available at http://www-01.ibm.com/support/docview.wss?uid=isg1IV08255.