Webmin, Usermin: Format string vulnerability — GLSA 200512-02

Webmin and Usermin are vulnerable to a format string vulnerability which may lead to the execution of arbitrary code.

Affected packages

app-admin/webmin on all architectures
Affected versions < 1.250
Unaffected versions >= 1.250
app-admin/usermin on all architectures
Affected versions < 1.180
Unaffected versions >= 1.180


Webmin is a web-based interface for Unix-like systems. Usermin is a simplified version of Webmin designed for use by normal users rather than system administrators.


Jack Louis discovered that the Webmin and Usermin "miniserv.pl" web server component is vulnerable to a Perl format string vulnerability. Login with the supplied username is logged via the Perl "syslog" facility in an unsafe manner.


A remote attacker can trigger this vulnerability via a specially crafted username containing format string data. This can be exploited to consume a large amount of CPU and memory resources on a vulnerable system, and possibly to execute arbitrary code of the attacker's choice with the permissions of the user running Webmin.


There is no known workaround at this time.


All Webmin users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=app-admin/webmin-1.250"

All Usermin users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=app-admin/usermin-1.180"


Release date
December 07, 2005

Latest revision
December 07, 2005: 01



Bugzilla entries