Operating System:

Published:

24 October 2000

Protect yourself against future threats.

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              AUSCERT External Security Bulletin Redistribution
                             
                      ESB-2000.304 -- RHSA-2000:086-05
         ypbind for Red Hat Linux 5.x, 6.x has a local root exploit
                               25 October 2000

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	AusCERT Security Bulletin Summary
	---------------------------------

Product:                ypbind
Vendor:                 Red Hat
Operating System:       Red Hat Linux 5.X, 6.X
Impact:                 Root Compromise
Access Required:        Local

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                   Red Hat, Inc. Security Advisory

Synopsis:          ypbind for Red Hat Linux 5.x, 6.x has a local root exploit
Advisory ID:       RHSA-2000:086-05
Issue date:        2000-10-16
Updated on:        2000-10-23
Product:           Red Hat Linux
Keywords:          ypbind string format buffer overflow syslog
Cross references:  N/A
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1. Topic:

ypbind as shipped in Red Hat Linux 5.x and 6.x is vulnerable to a local
root exploit.  All systems making use of NIS services are encouraged to
upgrade.

2. Relevant releases/architectures:

Red Hat Linux 5.0 - i386, alpha, sparc
Red Hat Linux 5.1 - i386, alpha, sparc
Red Hat Linux 5.2 - i386, alpha, sparc
Red Hat Linux 6.0 - i386, alpha, sparc
Red Hat Linux 6.1 - i386, alpha, sparc
Red Hat Linux 6.2 - i386, alpha, sparc
Red Hat Linux 6.2EE - i386, alpha, sparc

3. Problem description:

Systems using Network Information Service, or NIS, use a daemon called
ypbind to request information from a NIS server.  This information is then
used by the local machine. The logging code in ypbind is vulnerable to a
printf string format attack which an attacker could exploit by passing
ypbind a carefully crafted request. This attack can successfully lead to
local root access.

This problem has been corrected with these new packages.

4. Solution:

If you do not use NIS, you should remove ypbind:

rpm -e ypbind

Otherwise, for each RPM for your particular architecture, run:

rpm -Fvh [filename]

where filename is the name of the RPM.

You should then make sure that the new ypbind is running by issuing:

/etc/rc.d/init.d/ypbind restart

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

N/A

6. RPMs required:

Red Hat Linux 5.x:

alpha:
ftp://updates.redhat.com/5.2/alpha/ypbind-3.3-10.alpha.rpm

sparc:
ftp://updates.redhat.com/5.2/sparc/ypbind-3.3-10.sparc.rpm

i386:
ftp://updates.redhat.com/5.2/i386/ypbind-3.3-10.i386.rpm

sources:
ftp://updates.redhat.com/5.2/SRPMS/ypbind-3.3-10.src.rpm

Red Hat Linux 6.x:

alpha:
ftp://updates.redhat.com/6.2/alpha/ypbind-1.7-0.6.x.alpha.rpm

sparc:
ftp://updates.redhat.com/6.2/sparc/ypbind-1.7-0.6.x.sparc.rpm

i386:
ftp://updates.redhat.com/6.2/i386/ypbind-1.7-0.6.x.i386.rpm

sources:
ftp://updates.redhat.com/6.2/SRPMS/ypbind-1.7-0.6.x.src.rpm

7. Verification:

MD5 sum                           Package Name
- --------------------------------------------------------------------------
507ff0e63468e829b2c917789ba2fedd  5.2/SRPMS/ypbind-3.3-10.src.rpm
127274f9828d27f895e8d8eee8d38db6  5.2/alpha/ypbind-3.3-10.alpha.rpm
7bbf68a42a3c996c6f69b5ffaf2911f7  5.2/i386/ypbind-3.3-10.i386.rpm
3d0cd8b8700182b9b815525e1f99c82d  5.2/sparc/ypbind-3.3-10.sparc.rpm
d8caa439a1b6c7b26f843bacd01c65f8  6.2/SRPMS/ypbind-1.7-0.6.x.src.rpm
3a426e3060d31aa37b2a41d973ac3f63  6.2/alpha/ypbind-1.7-0.6.x.alpha.rpm
411017238af9a0a8891bd3078547336c  6.2/i386/ypbind-1.7-0.6.x.i386.rpm
3beff51d6a0292fd9d50fe24d07097ac  6.2/sparc/ypbind-1.7-0.6.x.sparc.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>

8. References:

N/A


Copyright(c) 2000 Red Hat, Inc.

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