---------------------------------------------------------------------

                   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

---------------------------------------------------------------------



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:

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



sparc:

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



i386:

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



sources:

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



Red Hat Linux 6.x:



alpha:

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



sparc:

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



i386:

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



sources:

http://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  



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 



8. References:



N/A





Copyright(c) 2000 Red Hat, Inc.