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SuSE Linux Advisory: nfs-utils

Jul 15, 2003, 14:29 (0 Talkback[s])

SuSE Security Announcement

Package: nfs-utils
Announcement-ID: SuSE-SA:2003:031
Date: Tue Jul 15 14:00:00 MEST 2003
Affected products: 7.2, 7.3, 8.0, 8.1, 8.2 SuSE Linux Database Server, SuSE eMail Server III, 3.1 SuSE Linux Enterprise Server 7, 8 SuSE Linux Firewall on CD/Admin host SuSE Linux Connectivity Server SuSE Linux Office Server SuSE Linux Desktop 1.0
Vulnerability Type: remote code execution
Severity (1-10): 7
SuSE default package: yes
Cross References: CAN-2003-0252 http://isec.pl/vulnerabilities/

Content of this advisory:

  1. security vulnerability resolved: Off by one bug in rpc.mountd. problem description, discussion, solution and upgrade information
  2. pending vulnerabilities, solutions, workarounds:
    • xpdf/acroread
    • lbreakout
    • Eterm
    • gnats
    • unzip
  3. standard appendix (further information)

1) problem description, brief discussion, solution, upgrade information

The nfs-utils package contains various programs to offer and manage certain RPC services such as the rpc.mountd. iSEC Security Research has reported an off-by-one bug in the xlog() function used by the rpc.mountd. It is possible for remote attackers to use this off-by-one overflow to execute arbitrary code as root. Some of the products listed above seem not vulnerable to this one byte overflow due to the stack alignment generated by the compiler during the build. Nevertheless, since there is no easy workaround except shutting down the RPC services, an update is strongly recommended for every product listed above.

This update needs to be applied to both NFS servers and clients, as the vulnerable function is used by mountd and statd.

You can either restart these services manually, or use the corresponding init scripts:

"rcnfsserver restart" (for the NFS server)
"rcnfs restart" (for the NFS client)

Depending on your setup, it may be less disruptive to restart the two daemons manually.

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.

i386 Intel Platform:

SuSE-8.2:
ftp://ftp.suse.com/pub/suse/i386/update/8.2/rpm/i586/nfs-utils-1.0.1-109.i586.rpm 964386359a4280b0f64b5d06cc0debb4
patch rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/8.2/rpm/i586/nfs-utils-1.0.1-109.i586.patch.rpm 5e67e844aa5d5c9d6fb3720f388813af
source rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/8.2/rpm/src/nfs-utils-1.0.1-109.src.rpm 91695f1d03df64188c3a63126699a811

SuSE-8.1:
ftp://ftp.suse.com/pub/suse/i386/update/8.1/rpm/i586/nfs-utils-1.0.1-109.i586.rpm b212711af6445cb97773e30ed4284741
patch rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/8.1/rpm/i586/nfs-utils-1.0.1-109.i586.patch.rpm 8b267ea76f715f64b8a041c2f24cee07
source rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/8.1/rpm/src/nfs-utils-1.0.1-109.src.rpm 6da708a468ca48dd4078cbeff2c842f6

SuSE-8.0:
ftp://ftp.suse.com/pub/suse/i386/update/8.0/n1/nfs-utils-0.3.3-178.i386.rpm 3cec45e5a7fdac0e9d6c67d894e90b16
patch rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/8.0/n1/nfs-utils-0.3.3-178.i386.patch.rpm 5f86c33e9564e39df6f74c376d6d0ccd
source rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/8.0/zq1/nfs-utils-0.3.3-178.src.rpm f105acb95d3a770c4b142fd265bdf6a7

SuSE-7.3:
ftp://ftp.suse.com/pub/suse/i386/update/7.3/n1/nfs-utils-0.3.1-111.i386.rpm a4c43c562fc1d9ff65367795897d5fb5
source rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/7.3/zq1/nfs-utils-0.3.1-111.src.rpm dc56ab3deeb7a5ed6bde4e021ff35c10

SuSE-7.2:
ftp://ftp.suse.com/pub/suse/i386/update/7.2/n1/nfs-utils-0.3.1-112.i386.rpm 1905a8a632eaf00dd5ad81f498ad6493
source rpm(s):
ftp://ftp.suse.com/pub/suse/i386/update/7.2/zq1/nfs-utils-0.3.1-112.src.rpm a048236b106c8a32bce936a39bdc0403

Sparc Platform:

SuSE-7.3:
ftp://ftp.suse.com/pub/suse/sparc/update/7.3/n1/nfs-utils-0.3.1-49.sparc.rpm 176b1636fa49520b3f700d399af39203
source rpm(s):
ftp://ftp.suse.com/pub/suse/sparc/update/7.3/zq1/nfs-utils-0.3.1-49.src.rpm 2b3cd21df36acf2b6076993855ef179f

PPC Power PC Platform:

SuSE-7.3:
ftp://ftp.suse.com/pub/suse/ppc/update/7.3/n1/nfs-utils-0.3.1-60.ppc.rpm 0af7e6f702231a3194063a2c99473bb4
source rpm(s):
ftp://ftp.suse.com/pub/suse/ppc/update/7.3/zq1/nfs-utils-0.3.1-60.src.rpm 6b4a8ea3c5e443d255e15123dc97b0e9


2) Pending vulnerabilities in SuSE Distributions and Workarounds:

  • xpdf/acroread A problem regarding handling of external URLs by various PDF readers has been reported by CERT. Attackers could execute arbitrary commands as the user viewing the document by embedding shell meta characters in URLs. The xpdf PDF viewer as shipped with SuSE is not vulnerable to this attack due to its configuration. For the acrobat PDF reader we will provide updates on our ftp servers shortly.
  • lbreakout Various format string bugs in the code of the game lbreakout were reported for version 2-2.5. These bugs can be exploited remotely. SuSE Linux does not ship this vulnerable version of lbreakout.
  • Eterm A buffer overflow in eterm while handling the environment variable ETERMPATH can lead to local privilege escalation. SuSE do not ship eterm with higher privileges.
  • gnats Several security bugs were reported in gnats. These bugs will be fixed and update packages will released soon.
  • unzip Unzip can be tricked into overwriting files by using special zip archives. Fixed packages are available on our ftp servers.

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 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.
  4. rpm package signatures provide an easy way to verify the authenticity of an rpm package. Use the command rpm -v --checksig to verify the signature of the package, where 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 "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 subscribe:

suse-security@suse.com

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

    <<A HREF="mailto:suse-security-subscribe@suse.com">suse-security-subscribe@suse.com>.

suse-security-announce@suse.com

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

    <<A HREF="mailto:suse-security-announce-subscribe@suse.com">suse-security-announce-subscribe@suse.com>.

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

<<A HREF="mailto:suse-security-info@suse.com">suse-security-info@suse.com> or
<<A HREF="mailto:suse-security-faq@suse.com">suse-security-faq@suse.com> respectively.


SuSE's security contact is <<A HREF="mailto:security@suse.com">security@suse.com> or <<A HREF="mailto:security@suse.de">security@suse.de>. The <<A HREF="mailto:security@suse.de">security@suse.de> 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.

Type Bits/KeyID Date User ID
pub 2048R/3D25D3D9 1999-03-06 SuSE Security Team <<A HREF="mailto:security@suse.de">security@suse.de>
pub 1024D/9C800ACA 2000-10-19 SuSE Package Signing Key <<A HREF="mailto:build@suse.de">build@suse.de>