Package: scotty
Announcement-ID: SuSE-SA:2001:023
Date: Monday, Jul 2nd 2001 15:30 MEST
Affected SuSE versions: (6.0, 6.1, 6.2,) 6.3, 6.4, 7.0, 7.1,
7.2
Vulnerability Type: local privilege escalation
Severity (1-10): 5
SuSE default package: no
Other affected systems: yes
Content of this advisory:
1) security vulnerability resolved: scotty/ntping
problem description, discussion, solution and upgrade
information
2) pending vulnerabilities, solutions, workarounds
3) standard appendix (further information)
1) problem description, brief discussion, solution, upgrade
information
Tkined's Scotty is a Tcl extension to build network management
applications. Ntping, a ping/traceroute program, is part of the
Scotty package.
It's failure is to read a hostname as commandline option without
checking
the size. This leads to a bufferoverrun, that could be used to gain
root privileges,
because ntping is installed setuid root and is executeable by
everyone.
As a temporary workaround you could remove the setuid bit:
/bin/chmod u-s /usr/bin/ntping
or just allow trusted users the access the binary:
/bin/chown root.trusted /usr/bin/ntping
/bin/chmod 4750 /usr/bin/ntping
Also add these permission changes to /etc/permissions.local.
2) Pending vulnerabilities in SuSE Distributions and
Workarounds:
- dqs
dex@raza-mexicana.org has found an exploitable buffer overflow bug
in
the dsh program from the dqs package on SuSE Linux
distributions.
To workaround the problem, do "chmod -s /usr/bin/dsh" and change
the
files /etc/permissions* to reflect the change. If you do not need
the
dqs package, then deinstall it (rpm -e dqs).
Packages for most of the supported SuSE Linux distributions are
available at the usual location
ftp://ftp.suse.com/pub/suse/<arch>/<dist>
for download and installation/update. Do not forget to change the
files
/etc/permissions* to remove the suid-bit from the dsh program.
Please
note that we will not issue a dedicated security announcement for
this
specific bug.
- pcp
Paul Starzetz discovered a security weakness in the setuid root
program
/usr/share/pcp/bin/pmpost. The common library in pcp trusts the
environment that has been supplied by the user, regardless of
privileged
execution or not. By consequence, a user can specify the
configuration
file and therefore write to files owned by root. The problem is not
based
on insecurely following symlinks as stated by Paul Starzetz.
The pcp package is not installed by default in SuSE Linux
distributions.
We have provided update packages for the SuSE Linux distributions
version
7.1 and 7.2 that remove the setuid bit from the pmpost binary.
Versions
before SuSE-7.1 were not affected because the setuid bit was not
set.
We thank Keith Owens and Mark Goodwin from Silicon Graphics for
responding
quickly and for publishing a new version of the pcp package which
will
be included in future releases of the SuSE Linux distribution. For
more
information see the /usr/share/doc/packages/pcp directory of your
SuSE
Linux installation after installing the update package, or go
to
obtained from http://oss.sgi.com/projects/pcp/download .
Please note that there will not be a dedicated security
announcement
for this specific bug.
- fetchmail (fetchml)
New fetchmail packages are available on the ftp server. The
packages
cure a buffer overflow that can be exploited by sending a victim
a
specially designed email, waiting for the victim's fetchmail
program
to pick up the email. We are preparing a security announcement for
this
problem.
- openssh
update packages for the openssh package after (and including)
SuSE-6.4
are available on our ftp servers ftp.suse.de (for < 7.1) or
ftp.suse.com (for >= 7.1). We are currently checking for a
non-security
related irregularity in sshd's behaviour under faulty setup
conditions.
- exim
SuSE Linux distributions do not contain the exim Mail Transport
Agent
(See http://www.exim.org/ for details) and are therefore not
susceptible
to the recently found security-related bugs.
- webmin
SuSE Linux distributions do not contain the webmin
administration
web frontend (See http://www.webmin.org/ for details) and are
therefore
not vulnerable to the recently found security-related problems in
the
software.
3) standard appendix: authenticity verification, additional
information
- Package authenticity verification:
SuSE update packages are available on many mirror ftp servers all
over
the world. While this service is being considered valuable and
important
to the free and open source software community, many users wish to
be
sure about the origin of the package and its content before
installing
the package. There are two verification methods that can be
used
independently from each other to prove the authenticity of a
downloaded
file or rpm package:
1) md5sums as provided in the (cryptographically signed)
announcement.
2) using the internal gpg signatures of the rpm package.
1) execute the command
md5sum <name-of-the-file.rpm>
after you downloaded the file from a SuSE ftp server or its
mirrors.
Then, compare the resulting md5sum with the one that is listed in
the
announcement. Since the announcement containing the checksums
is
cryptographically signed (usually using the key
security@suse.de),
the checksums show proof of the authenticity of the package.
We disrecommend to subscribe to security lists which cause the
email message containing the announcement to be modified so
that
the signature does not match after transport through the
mailing
list software.
Downsides: You must be able to verify the authenticity of the
announcement in the first place. If RPM packages are being
rebuilt
and a new version of a package is published on the ftp server,
all
md5 sums for the files are useless.
2) rpm package signatures provide an easy way to verify the
authenticity
of an rpm package. Use the command
rpm -v --checksig <file.rpm>
to verify the signature of the package, where <file.rpm> is
the
filename of the rpm package that you have downloaded. Of
course,
package authenticity verification can only target an uninstalled
rpm
package file.
Prerequisites:
a) gpg is installed
b) The package is signed using a certain key. The public part of
this
key must be installed by the gpg program in the directory
~/.gnupg/ under the user's home directory who performs the
signature verification (usually root). You can import the key
that is used by SuSE in rpm packages for SuSE Linux by saving
this announcement to a file ("announcement.txt") and
running the command (do "su -" to be root):
gpg --batch; gpg < announcement.txt | gpg --import
SuSE Linux distributions version 7.1 and thereafter install the
key "build@suse.de" upon installation or upgrade, provided that
the package gpg is installed. The file containing the public
key
is placed at the toplevel directory of the first CD
(pubring.gpg)
and at ftp://ftp.suse.com/pub/suse/pubring.gpg-build.suse.de
.
