Operating System:

Published:

11 November 1999

Protect yourself against future threats.

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===========================================================================
              AUSCERT External Security Bulletin Redistribution
                             
                      ESB-1999.172 -- RHSA-1999:053-01
                new NFS server packages available (5.2, 4.2)
                              12 November 1999

===========================================================================

Red Hat Inc. has released the following advisory concerning a buffer
overflow vulnerability in the user space NFS daemon that ships with Red Hat
Linux 4.2 and 5.2.

This vulnerability may be exploited to allow users to execute arbitrary
code as the owner of the NFS daemon if they have read/write access to
a share on the affected server.

This may allow remote users to gain root access.

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- ---------------------------------------------------------------------
		   Red Hat, Inc. Security Advisory

Synopsis:		new NFS server packages available (5.2, 4.2)
Advisory ID:		RHSA-1999:053-01
Issue date:		1999-11-11
Updated on:		1999-11-11	
Keywords:		nfs-server PATH_MAX NAME_MAX rpc.nfsd
Cross references:	Bugtraq id #782
- ---------------------------------------------------------------------

1. Topic:

A buffer overflow exists in the user space NFS daemon that
shipped with Red Hat Linux 4.2 and 5.2.

2. Relevant releases/architectures:

Red Hat Linux 4.x, all platforms
Red Hat Linux 5.x, all platforms

Red Hat Linux 6.x uses the knfsd kernel space NFS daemon,
and is not affected by this problem.

3. Problem description:

The length of a path name was not checked on the
removal of a directory. If a long enough directory name
was created, the buffer holding the pathname would
overflow, and the possibility exists that arbitrary
code could be executed as the user the NFS server runs
as (root). Exploiting this buffer overflow does require
read/write access to a share on an affected server.

4. Solution:

It is recommended that all users of Red Hat Linux 4.x
and 5.x update to the fixed packages.

Thanks go to Olaf Kirch (okir@monad.swb.de) for providing
a fix.

For each RPM for your particular architecture, run:
    rpm -Uvh <filename>
where filename is the name of the RPM.

5. Bug IDs fixed (http://developer.redhat.com/bugzilla for more info):

6. Obsoleted by:

7. Conflicts with:

8. RPMs required:

Red Hat Linux 4.x:

Intel:
  ftp://updates.redhat.com/4.2/i386/nfs-server-2.2beta47-0.i386.rpm
  ftp://updates.redhat.com/4.2/i386/nfs-server-clients-2.2beta47-0.i386.rpm

Alpha:
  ftp://updates.redhat.com/4.2/alpha/nfs-server-2.2beta47-0.alpha.rpm
  ftp://updates.redhat.com/4.2/alpha/nfs-server-clients-2.2beta47-0.alpha.rpm

Sparc:
  ftp://updates.redhat.com/4.2/sparc/nfs-server-2.2beta47-0.sparc.rpm
  ftp://updates.redhat.com/4.2/sparc/nfs-server-clients-2.2beta47-0.sparc.rpm

Source packages:
  ftp://updates.redhat.com/4.2/SRPMS/nfs-server-2.2beta47-0.src.rpm

Red Hat Linux 5.x:

Intel:
  ftp://updates.redhat.com/5.2/i386/nfs-server-2.2beta47-1.i386.rpm
  ftp://updates.redhat.com/5.2/i386/nfs-server-clients-2.2beta47-1.i386.rpm

Alpha:
  ftp://updates.redhat.com/5.2/alpha/nfs-server-2.2beta47-1.alpha.rpm
  ftp://updates.redhat.com/5.2/alpha/nfs-server-clients-2.2beta47-1.alpha.rpm

Sparc:
  ftp://updates.redhat.com/5.2/sparc/nfs-server-2.2beta47-1.sparc.rpm
  ftp://updates.redhat.com/5.2/sparc/nfs-server-clients-2.2beta47-1.sparc.rpm

Source packages:
  ftp://updates.redhat.com/5.2/SRPMS/nfs-server-2.2beta47-1.src.rpm

9. Verification:

MD5 sum                           Package Name
- --------------------------------------------------------------------------
09b6c7ff370f58140aac7d1a41b50035  i386/nfs-server-2.2beta47-0.i386.rpm
14e1e5e5bcba01f9bb9cb6dfe9e2627e  i386/nfs-server-clients-2.2beta47-0.i386.rpm
9ce6b7afd8ef5a1d5b481ee9fe2530d3  alpha/nfs-server-2.2beta47-0.alpha.rpm
6306ba518cd64b0d018b8b2786ecb128  alpha/nfs-server-clients-2.2beta47-0.alpha.rpm
cf15f95dd9b13844b63a9e7607a873ee  sparc/nfs-server-2.2beta47-0.sparc.rpm
a450ee5b850fb6ed906b3527a2165ec5  sparc/nfs-server-clients-2.2beta47-0.sparc.rpm
e6ffef85c75620ebebf0c3244a181c46  SRPMS/nfs-server-2.2beta47-0.src.rpm

1d408903070fa5313072fe8886917bda  i386/nfs-server-2.2beta47-1.i386.rpm
e4c30ae30f3cbdd4ff2cd90232c46e0e  i386/nfs-server-clients-2.2beta47-1.i386.rpm
1d6f0a6c28b4cb20e1f203bb8d376af1  alpha/nfs-server-2.2beta47-1.alpha.rpm
75f89bcd51df6771d993aaee6f812ce7  alpha/nfs-server-clients-2.2beta47-1.alpha.rpm
0dc37d253e7620ce300ef51b15af562b  sparc/nfs-server-2.2beta47-1.sparc.rpm
21c743b1631db675dd1aac7007c9a37a  sparc/nfs-server-clients-2.2beta47-1.sparc.rpm
810ca1bd9d362031ed21c664eb2024ac  SRPMS/nfs-server-2.2beta47-1.src.rpm

These packages are GPG signed by Red Hat, Inc. for security.  Our key
is available at:
    http://www.redhat.com/corp/contact.html
 
You can verify each package with the following command:
    rpm --checksig  <filename>

If you only wish to verify that each package has not been corrupted or
tampered with, examine only the md5sum with the following command:
    rpm --checksig --nogpg <filename>

10. References:

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