VMware Workstation Shared Folders Feature Lets Users Read/Write Arbitrary Files
SecurityTracker Alert ID: 1017980|
SecurityTracker URL: http://securitytracker.com/id/1017980
(Links to External Site)
Updated: May 8 2007|
Original Entry Date: Apr 30 2007
Disclosure of system information, Disclosure of user information, Modification of system information, Modification of user information|
Fix Available: Yes Vendor Confirmed: Yes |
Version(s): 5.5.3 build 34685, possibly other versions|
A vulnerability was reported in VMware Workstation. A user can read or write files on the target system.|
The 'Shared Folders' feature does not properly validate user-supplied input in filenames. If the 'Shared Folders' feature is enabled and at least one folder is shared, a user on the guest system can exploit the 'Backdoor I/O Port' interface to view files on target system that are located outside of the shared directory. If the shared directory provides write privileges, the user on the guest system can write arbitrary files to the target system.
The vendor was notified on March 20, 2007.
Greg MacManus of iDefense Labs discovered this vulnerability.
A user on a guest system can read or write files on the target system.|
The vendor has issued a fixed version (5.5.4), available at:|
Vendor URL: www.vmware.com/ (Links to External Site)
Access control error, Input validation error|
Source Message Contents
Subject: iDefense Security Advisory 04.27.07: VMware Workstation Shared Folders|
VMware Workstation Shared Folders Directory Traversal Vulnerability
iDefense Security Advisory 04.27.07
Apr 27, 2007
VMware Workstation is a software virtualization system which allows
multiple virtual computers to run on a single system. For more
information visit the following URL.
Remote exploitation of a design error in the "Shared Folders" feature of
VMware Inc.'s VMware Workstation could allow an attacker to write
arbitrary content from a guest system to arbitrary locations on the
The "Shared Folders" feature of VMware Workstation allows folders on the
physical "host" system to be shared with virtual "guest" systems. Due to
a flaw in the code which validates that the filename is safe, an
attacker or malicious code within the guest system can read or write
files on the host system in the context of the user running
Exploitation allows an attacker to read or write arbitrary files on the
In order to exploit this vulnerability, the VMware system must have at
least one folder shared. Although the "Shared Folders" feature is
enabled by default, no folders are shared by default. If the 'Read
Only' option for a shared folder is set, the attacker will only be able
to read files from the host.
The documentation states that VMware Tools must be installed in order to
use the "Shared Folders" feature. While this is true of normal use of
the feature, VMware Tools is not required to exploit this
vulnerability. The vulnerable functionality is supplied by the
"Backdoor I/O Port" interface. Some details of the interface protocol
are publicly available. These details provide a starting point which
allow an attacker to reverse engineer enough of the protocol to
implement their own tool for performing these operations.
iDefense confirmed this vulnerability to exist in VMware Workstation
5.5.3 build 34685 on a Windows XPSP2 host. Other versions may also be
Disabling the "Shared Folders" feature in VMware will prevent exposure
to this vulnerability.
VI. VENDOR RESPONSE
VMware Inc. has addressed this vulnerability by releasing new versions
of their software. More information is available in the release notes
provided by VMware Inc.
VII. CVE INFORMATION
The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2007-1744 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which standardizes names for
VIII. DISCLOSURE TIMELINE
03/20/2007 Initial vendor notification
03/20/2007 Initial vendor response
04/27/2007 Coordinated public disclosure
This vulnerability was discovered by Greg MacManus of iDefense Labs.
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