Date: Mon, 24 Jan 2000 08:48:43 -0600
From: harikiri <[email protected]>
To: [email protected]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 <[email protected]>
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
