Webmin, Usermin: Multiple vulnerabilities in Usermin

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200409-15 / Usermin
Release Date	September 12, 2004
Latest Revision	May 22, 2006: 02
Impact	normal
Exploitable	remote

Package	Vulnerable versions	Unaffected versions	Architecture(s)
app-admin/usermin	< 1.090	>= 1.090	All supported architectures
app-admin/webmin	< 1.160	>= 1.160	All supported architectures

Related bugreports: #63167

Synopsis

A vulnerability in the webmail function of Usermin could be used by an attacker to execute shell code via a specially-crafted e-mail. A bug in the installation script of Webmin and Usermin also allows a local user to execute a symlink attack at installation time.

2. Impact Information

Background

Webmin and Usermin are web-based system administration consoles. Webmin allows an administrator to easily configure servers and other features. Usermin allows users to configure their own accounts, execute commands, and read e-mail. The Usermin functionality, including webmail, is also included in Webmin.

Description

There is an input validation bug in the webmail feature of Usermin.

Additionally, the Webmin and Usermin installation scripts write to /tmp/.webmin without properly checking if it exists first.

Impact

The first vulnerability allows a remote attacker to inject arbitrary shell code in a specially-crafted e-mail. This could lead to remote code execution with the privileges of the user running Webmin or Usermin.

The second could allow local users who know Webmin or Usermin is going to be installed to have arbitrary files be overwritten by creating a symlink by the name /tmp/.webmin that points to some target file, e.g. /etc/passwd.

3. Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All Usermin users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge sync

# emerge -pv ">=app-admin/usermin-1.090"
# emerge ">=app-admin/usermin-1.090"

All Webmin users should upgrade to the latest version:

Code Listing 3.2: Resolution

# emerge sync

# emerge -pv ">=app-admin/webmin-1.160"
# emerge ">=app-admin/webmin-1.160"

4. References

Updated September 12, 2004

Summary: This is a Gentoo Linux Security Advisory

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