Ver la Versión Completa : Aviso de seguridad

04-ago-2004, 23:19
SUSE Security Announcement

Package: libpng
Announcement-ID: SUSE-SA:2004:023
Date: Wednesday, Aug 4th 2004 16:00 MEST
Affected products: 8.0, 8.1, 8.2, 9.0, 9.1
SUSE Linux Database Server,
SUSE eMail Server III, 3.1
SUSE Linux Enterprise Server 7, 8, 9
SUSE Linux Firewall on CD/Admin host
SUSE Linux Connectivity Server
SUSE Linux Office Server
Vulnerability Type: remote system compromise
Severity (1-10): 9
SUSE default package: yes
Cross References: VU#388984

Content of this advisory:
1) security vulnerability resolved:
- stack based buffer overflows
- NULL pointer dereference
- integer overflows
problem description
2) solution/workaround
3) special instructions and notes
4) package location and checksums
5) pending vulnerabilities, solutions, workarounds:
- mod_ssl
- lha
- gfxboot
- liby2util
- pure-ftpd
- neon
- pavuk
- sox
- gaim
- kernel
6) standard appendix (further information)

__________________________________________________ ____________________________

1) problem description, brief discussion

Several different security vulnerabilities were found in the PNG
library which is used by applications to support the PNG image format.

A remote attacker is able to execute arbitrary code by triggering a
buffer overflow due to the incorrect handling of the length of
transparency chunk data and in other pathes of image processing.
(VU#388984, VU#817368, CAN-2004-0597)
A special PNG image can be used to cause an application crashing due
to NULL pointer dereference in the function png_handle_iCPP() (and
other locations). (VU#236656, CAN-2004-0598)
Integer overflows were found in png_handle_sPLT(), png_read_png()
functions and other locations. These bugs may at least crash an
application. (VU#160448, VU#477512, VU#286464, CAN-2004-0599)

Many thanks to Chris Evans who reported issues to us and other vendors.

3) special instructions and notes

Various applications use libpng either dynamically linked, statically
linked, or by linking a copy of libpng included in the application's
source distribution.
In the first case you have to restart the affected application.
In the other cases we will release updates for these packages if the
vulnerable libpng code is called with input from an untrusted source.

4) package location and checksums

Please download the update package for your distribution and verify its
integrity by the methods listed in section 3) of this announcement.
Then, install the package using the command "rpm -Fhv file.rpm" to apply
the update.
Our maintenance customers are being notified individually. The packages
are being offered to install from the maintenance web.

x86 Platform:

SUSE Linux 9.1:
patch rpm(s):
source rpm(s):

SUSE Linux 9.0:
patch rpm(s):
source rpm(s):

SUSE Linux 8.2:
patch rpm(s):
source rpm(s):

SUSE Linux 8.1:
patch rpm(s):
source rpm(s):

SUSE Linux 8.0:
patch rpm(s):
source rpm(s):

x86-64 Platform:

SUSE Linux 9.1:
patch rpm(s):
source rpm(s):

SUSE Linux 9.0:
patch rpm(s):
source rpm(s):

__________________________________________________ ____________________________

5) Pending vulnerabilities in SUSE Distributions and Workarounds:

- mod_ssl
A remotely exploitable format string bug has been found in the
logging function of mod_ssl.
New packages are available at our FTP servers.

- lha
A source code review of lha was conducted by the SuSE Security-Team
to fix all possible buffer overflows.
New packages are available at our FTP servers.

- gfxboot/bootsplash-theme-SuSE/bootsplash-theme-SuSE-Home
A bug in gfxboot on SUSE LINUX 9.1 caused the lilo boot password
to be shown in cleartext while typing.
The standard boot loader is grub.
New packages are available at our FTP servers.

- liby2util
File names of patch files are no longer passed to gpg via the
system() call. Since those file names are not protected by a digital
signature, an attacker could previously manage to implant shell
New packages are available at our FTP servers.

- pure-ftpd
This update fixes a possible DoS attack because of a bug in the
accept_client function handling the setup of new connections.
New packages are available at our FTP servers.

- neon
This update adds a missing filter for control characters.
New packages are available at our FTP servers.

- pavuk
This update fixes several buffer overflows in pavuk's digest
authentication support. Thanks to Matthew Murphy for reporting
this issue to us.
New packages are available at our FTP servers.

- sox
Several buffer overflows in the 'sox' and 'play' have been fixed that
can be exploited by playing specially crafted .wav files. (CAN-2004-0557)
New packages are available at our FTP servers.

- gaim
The SuSE Security Team discovers various remotely exploitable buffer
overflows in the MSN-protocol parsing functions of gaim. The only
affected product is SUSE LINUX 9.1.
New packages will be available soon. (CAN-2004-0500)

- kernel
Paul Starzetz from iSEC informed us about a race condition in the 64bit
file offset handling code of the kernel.
New kernels for SUSE LINUX Enterprise Server 9 are available from
the maintenance-web. The updates for the SUSE LINUX 9.1 kernels are
available from our FTP servers.
Kernel update packages for older SUSE LINUX distributions will be
available in the next few days and will be announced with a dedicated

__________________________________________________ ____________________________

6) 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 un-installed rpm
package file.
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 top-level directory of the first CD (pubring.gpg)
and at ftp://ftp.suse.com/pub/suse/pubring.gpg-build.suse.de .

- SUSE runs two security mailing lists to which any interested party may

- general/linux/SUSE security discussion.
All SUSE security announcements are sent to this list.
To subscribe, send an email to

- SUSE's announce-only mailing list.
Only SUSE's security announcements are sent to this list.
To subscribe, send an email to

05-ago-2004, 22:35
Pues gracias por la información kunael, acabo de actualizar el paquete ;)

Usando las actualizaciones online automáticas aparece para instalarlo, así que no hay problema


Un saludo :)