Webmin, Usermin: Format string vulnerability

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200512-02 / webmin usermin
Release Date	December 07, 2005
Latest Revision	December 07, 2005: 01
Impact	high
Exploitable	remote

Package	Vulnerable versions	Unaffected versions	Architecture(s)
app-admin/webmin	< 1.250	>= 1.250	All supported architectures
app-admin/usermin	< 1.180	>= 1.180	All supported architectures

Related bugreports: #113888

Synopsis

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

2. Impact Information

Background

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.

Description

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.

Impact

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.

3. Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All Webmin users should upgrade to the latest version:

Code Listing 3.1: Resolution

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

All Usermin users should upgrade to the latest version:

Code Listing 3.2: Resolution

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

4. References

Page updated December 07, 2005

Summary: This is a Gentoo Linux Security Advisory

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