The default installation of SAP R/3 46C/D allows remote attackers to bypass account locking by using the RFC API instead of the SAPGUI to conduct a brute force password guessing attack, which does not lock out the account like the SAPGUI does.
https://exchange.xforce.ibmcloud.com/vulnerabilities/11487
http://www.securityfocus.com/bid/7007
http://www.securityfocus.com/archive/1/451378/100/0/threaded
http://lists.grok.org.uk/pipermail/full-disclosure/2003-March/004039.html