OSEC

Neohapsis is currently accepting applications for employment. For more information, please visit our website www.neohapsis.com or email hr@neohapsis.com
Bugtraq Archives: Re: VMware 1.1.2 Symlink Vulnerability

Re: VMware 1.1.2 Symlink Vulnerability

Subject: Re: VMware 1.1.2 Symlink Vulnerability
From: Oinos (oinosMAIL.KB0RVE.ORG)
Date: Tue Jan 25 2000 - 00:23:12 CST

The use of the /tmp directory is default in VMware, but configurable with
the tmpDirectory = <directory> setting in the .cfg file for the guest
operating system, or with the TMPDIR=<directory> setting in your shell
environment. This is documented on VMware's website.

-Oinos

-----Original Message-----
From: Bugtraq List [mailto:BUGTRAQSECURITYFOCUS.COM]On Behalf Of harikiri
Sent: Monday, January 24, 2000 8:49 AM
To: BUGTRAQSECURITYFOCUS.COM
Subject: VMware 1.1.2 Symlink Vulnerability

w00w00 Security Advisory - http://www.w00w00.org/

Title: VMware 1.1.2 Symlink Vulnerability
Platforms: Linux Distributions with VMware 1.1.2 (build 364)
Discovered: 17th January, 2000
Local: Yes.
Remote: No.
Author: harikiri <harikiriattrition.org>
Vendor Status: Notified.
Last Updated: N/A

1. Overview

VMware stores temporary log files within the /tmp directory. It does
not check whether all of these files exist prior to creation, resulting
in the potential for a symlink attack.

2. Background

VMware is a commercial application that enables the operation of "guest"
operating systems within the host system. This is performed via the use of
Virtual Machine technology.

Due to the low-level requirements of VMware, it is necessary to run the
program at a high privilege level, typically root.

3. Issue

VMware creates the file "/tmp/vmware-log" on startup. The existance and
owner of the file is not checked prior to writing startup information to
the file.

NOTE: VMware uses other files in the /tmp directory. The one cited above
is only a single example.

4. Impact

Local users may create a symlink from an arbitrary file to /tmp/vmware-log.
When VMware is executed, the file pointed to by the symlink will be
overwritten.

This may be used as a local denial of service attack. There may also be a
method to gain elevated privileges via the symlink attack, though none is
known at this time.

5. Recommendation

Wait for a fix from the vendor.

6. References

- VMware Inc: http://www.vmware.com/
- w00w00 Security Development: http://www.w00w00.org/

EOF

This archive was generated by hypermail 2b27 : Tue Jan 25 2000 - 15:13:48 CST