source: https://www.securityfocus.com/bid/8989/info

Multiple command-line parameter format string vulnerabilities have been discovered in various IBM DB2 binaries. Specifically, format-based functions are implemented erroneously within the db2govd, db2start, and db2stop programs. These binaries are typically installed setuid. As a result, a malicious local user may be capable of gaining elevate privileges.

[kf@RiotStarter adm]$ ./db2stop %n%n
Segmentation fault