SuSE Linux Advisory: wu-ftpd

SuSE Security Announcement

Content of this advisory:

1. security vulnerability resolved: wuftpd 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

Janusz Niewiadomski and Wojciech Purczynski of iSEC Security
Research have found a single byte buffer overflow in the Washington
University ftp daemon (wuftpd), a widely used ftp server for
Linux-like systems. It is yet unclear if this bug is (remotely)
exploitable. Positive exploitability may result in a remote root
compromise of a system running the wuftpd ftp daemon.

Notes:

• SuSE Linux products do not contain wuftpd any more starting
  with SuSE Linux 8.0 and SuSE Linux Enterprise Server 8. The wuftpd
  package has been substituted by a different server implementation
  of the file transfer protocol server.
• The affected wuftpd packages in products as stated in the
  header of this announcement actually ship two different wuftpd ftp
  daemon versions: The older version 2.4.x that is installed as
  /usr/sbin/wu.ftpd, the newer version 2.6 is installed as
  /usr/sbin/wu.ftpd-2.6 . The 2.4.x version does not contain the
  defective parts of the code and is therefore not vulnerable to the
  weakness found.
• If you are using the wuftpd ftp daemon in version 2.4.x, you
  might want to update the package anyway in order not to risk an
  insecure configuration once you switch to the newer version.

There exists no workaround that can fix this vulnerability on a
temporary basis other than just using the 2.4.x version as
mentioned above. The proper fix for the weakness is to update the
package using the provided update packages.

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.

Intel i386 Platform:

SuSE-7.3:

ftp://ftp.suse.com/pub/suse/i386/update/7.3/n2/wuftpd-2.6.0-403.i386.rpm

9f786439f4efc289dbaee78a8c873b56
source rpm(s):

ftp://ftp.suse.com/pub/suse/i386/update/7.3/zq1/wuftpd-2.6.0-403.src.rpm

6f748bfc27cc44ade2c2044365fb825a

SuSE-7.2:

ftp://ftp.suse.com/pub/suse/i386/update/7.2/n2/wuftpd-2.6.0-403.i386.rpm

077463a6387d8b596cfedb6f80d765aa
source rpm(s):

ftp://ftp.suse.com/pub/suse/i386/update/7.2/zq1/wuftpd-2.6.0-403.src.rpm

5bd18ea86422a84338fc1827362e8bdc

Sparc Platform:

SuSE-7.3:

ftp://ftp.suse.com/pub/suse/sparc/update/7.3/n2/wuftpd-2.6.0-260.sparc.rpm

985a2bdcb25ec5283a00784810b28050
source rpm(s):

ftp://ftp.suse.com/pub/suse/sparc/update/7.3/zq1/wuftpd-2.6.0-260.src.rpm

49d647216d0f1b22a5a326887d8ef955

PPC Power PC Platform:

SuSE-7.3:

ftp://ftp.suse.com/pub/suse/ppc/update/7.3/n2/wuftpd-2.6.0-328.ppc.rpm

f8b1276d87cb5dcb4aca89054015a353
source rpm(s):

ftp://ftp.suse.com/pub/suse/ppc/update/7.3/zq1/wuftpd-2.6.0-328.src.rpm

07ff383965af6b860e5cfda95efa2fce

2) Pending vulnerabilities in SuSE Distributions and
Workarounds:

• gnats Several security bugs were reported in gnats. The version
  of gnats that comes with SuSE Linux is not vulnerable to these
  problems.
• kopete Kopete is the KDE instant messenger. A bug in kopete’s
  gpg plugin can be abused to execute commands remotely. A fix will
  be available as soon as possible.
• wget When handling long URLs, a buffer underrun may occur in
  the wget program. This underrun may be exploitable remotely. The
  update packages are available now on our ftp servers.
• emacs Due to insecure temporary file handling in the semi and
  wemi library of GNU Emacs it is possible for a local attacker to
  overwrite arbitrary files of the user running emacs. The fix is
  currently being worked on.
• ethereal Several remote exploitable bugs were found in the
  network analyzing tool ethereal. The update packages are available
  on our ftp servers.
• tomcat Wrong file permission and clear passwords in the tomcat
  default installation allows local users to gain security relevant
  data by reading the file /opt/jakarta/tomcat/conf/tomcat-users.xml.
  Please enable password encryption and revoke the read permissions
  for ‘group’ and ‘others’ by adding the following line to
  /etc/permissions.local:
  /opt/jakarta/tomcat/conf/tomcat-users.xml wwwrun.root 0700
  and run the following command as root:
  “chkstat -set /etc/permissions.local”
• heartbeat A format string bug in heartbeat’s debug code can be
  exploited by a remote attacker if the debug level is high and the
  heartbeat daemon in configuered in an unsecure manner. The update
  packages are being tested right now.
• freeradius A buffer overflow in the CHAP implementation of
  freeradius leads to a remotely exploitable security hole which can
  be abused to execute arbitrary code on the RADIUS server. The
  update packages are being tested right now.
• traceroute(-nanog) An integer overflow in traceroute-nanog can
  be abused to gain access to the raw ip socket. We are working on
  the fix.
• kdelibs Due to the fact of verifying the IP address instead of
  the Common Name (CN) field of the X.509 certificate the SSL
  implementation of KDE 2.2 and earlier is vulnerable to a MiM
  attack. Only SuSE Linux 7.3 is affected by this problem. Update
  packages are available on our FTP servers.
• man The mandb program which is part of the man package contains
  a buffer overflow which allows local attackers to execute arbitrary
  code as man user. New packages are already availabale on our ftp
  servers.
• several minor bug fixes There are alot more minor security
  updates in the queue. YOU (Yast Online Update) will inform you when
  they appear. Alternatively you may want to monitor the following
  website: http://www.suse.de/de/private/download/updates/index.html

  or:
  http://www.suse.de/en/private/download/updates/index.html

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.
3. 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 [email protected]), 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.
4. 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. Prerequisites:
   • gpg is installed
   • 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 “[email protected]”
     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 subscribe:

[email protected]

• general/linux/SuSE security discussion. All SuSE security
  announcements are sent to this list. To subscribe, send an email
  to
  <[email protected]>.

[email protected]

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

  <[email protected]>.

For general information or the frequently asked questions (faq)
send mail to:

        <[email protected]> or
        <[email protected]> respectively.

SuSE’s security contact is <[email protected]> or
<[email protected]>. The
<[email protected]>
public key is listed below.

The information in this advisory may be distributed or
reproduced, provided that the advisory is not modified in any way.
In particular, it is desired that the clear-text signature shows
proof of the authenticity of the text.
SuSE Linux AG makes no warranties of any kind whatsoever with
respect to the information contained in this security advisory.

Roman Drahtmüller,
SuSE Security.
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