Revised Patch for SunOS /usr/etc/rpc.mountd Vulnerability
Last revised: September 19, 1997
Attached copyright statement
A complete revision history is at the end of this file.
THIS IS A REVISED CERT ADVISORY
IT CONTAINS NEW VULNERABILITY AND PATCH INFORMATION
SUPERSEDES CERT ADVISORY CA-91.09 and CA-92.12
The CERT Coordination Center has received information concerning a vulnerability in /usr/etc/rpc.mountd in Sun Microsystems, Inc. SunOS 4.1.1, 4.1.2, 4.1.3, and 4.1.3c. SunOS 4.1.3.u.1, Solaris 2.x, and Solbourne's 4.1B and 4.1C are not vulnerable.
Sun has produced a patch for this vulnerability for sun3 and sun4 architectures. It is available through your local Sun Answer Center as well as through anonymous FTP from the ftp.uu.net system in the /systems/sun/sun-dist directory or from the ftp.eu.net system in the /sun/fixes directory.
This vulnerability is currently being exploited. Please review CERT Advisory CA-94.01 Ongoing Network Monitoring Attacks.
I. DescriptionIf an access list of hosts within /etc/exports is a string over 256 characters or if the cached list of netgroups exceeds the cache capacity then the file system can be mounted by anyone.
II. ImpactUnauthorized remote hosts will be able to mount the file system. This will allow unauthorized users read and write access to files on mounted file systems.
III. SolutionObtain and install the appropriate patch following the instructions included with the patch.
Patches are available from
There is a README file and directory layout to help identify which binaries are appropriate for which architectures.
Patch-ID Filename BSD MD5 Checksum Checksum 100296-04 100296-04.tar.Z 15271 40 4e1354ecb7fb9c7e962d7020f31f07bf
Copyright 1994, 1995, 1996 Carnegie Mellon University.
Sept. 19,1997 Attached copyright statement Aug. 30, 1996 Information previously in the README was inserted into the advisory. Updated URL format. June 09, 1995 Solution - recommended source to use for patches if the checksums didn't match Apr. 20, 1994 Solution - noted that Sun ensured that the same versions of patches were available at all locations and provided files to help determine which architectures require the patch.