Format string vulnerability in miniserv.pl Perl web server in Webmin before 1.250 and Usermin before 1.180, with syslog logging enabled, allows remote attackers to cause a denial of service (crash or memory consumption) and possibly execute arbitrary code via format string specifiers in the username parameter to the login form, which is ultimately used in a syslog call.  NOTE: the code execution might be associated with an issue in Perl.