The default installation of MSDE via McAfee ePolicy Orchestrator 2.0 through 3.0 allows attackers to execute arbitrary code via a series of steps that (1) obtain the database administrator username and encrypted password in a configuration file from the ePO server using a certain request, (2) crack the password due to weak cryptography, and (3) use the password to pass commands through xp_cmdshell.
http://www.nai.com/us/promos/mcafee/epo_vulnerabilities.asp
http://www.atstake.com/research/advisories/2003/a073103-1.txt