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SuSE Security Announcement: man

May 29, 2001, 19:53 (7 Talkback[s])
From: Roman Drahtmueller <>
Subject: [suse-security-announce] SuSE Security Announcement: man (SuSE-SA:2001:019)
Date: Tue, 29 May 2001 20:46:20 +0200 (MEST)


                        SuSE Security Announcement

        Package:                man
        Announcement-ID:        SuSE-SA:2001:019
        Date:                   Tuesday, May 29th 2001 20:30 MEST
        Affected SuSE versions: 6.0, 6.1, 6.2, 6.3, 6.4, 7.0, 7.1
        Vulnerability Type:     local privilege escalation
        Severity (1-10):        4
        SuSE default package:   yes
        Other affected systems: most linux systems shipping the mandb package

    Content of this advisory:
        1) security vulnerability resolved: man
           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

    Two vulnerabilities have been found in the man package that is installed
    by default in all SuSE Linux distributions. The first error is a format
    string bug in the error handling routine of the man command that can
    allow a local attacker to gain the privileges of the user "man" on SuSE
    Linux systems (the man command in /usr/bin is installed setuid man).
    After getting write access to the /usr/bin/man binary, an attacker can
    place a cuckook's egg into the executable, waiting for root to view
    The second problem is a segmentation fault that can be caused by the
    options "-S ::: foo" to the man command. On other Linux distributions,
    this problem has been found exploitable. On SuSE and Debian systems, the
    code responsible for the bug is different from the one found in other
    distributions and is not exploitable. We consider the existence of this
    bug a beauty flaw that will be fixed in future releases of the SuSE Linux
    distribution, but the fix was not included in the man packages that can
    be found on our ftp server.
    Since the error() format string bug was discovered earlier than we
    announced that the SuSE Linux distributions 6.0, 6.1 and 6.2 will be
    discontinued, we also provide fixed packages for the said distributions
    for the i386 Intel architecture. We strongly encourage our usership to
    upgrade their systems to a newer distribution.
    Both bugs are fixed in the upcoming release of SuSE Linux 7.2.

    A temporary workaround (as discussed in earlier SuSE security
    announcements) is to remove the setuid-bit of the /usr/bin/man file.
    This will cause errors to be printed when viewing a manpage, because
    the formatted manpages can't be saved to the /var/cache/man directories
    any longer. The sideeffects of this workaround are of mostly cosmetical
    nature on fast hardware.
    If you changed the file modes of the man command binary using the command
        chmod 755 /usr/bin/man
    , then please also change the occurrences of the same path in the files
    /etc/permissions*, provided you have set the variable CHECK_PERMISSIONS
    to "set" in /etc/rc.config.

    Download the update package from locations described below and check the
    authenticity of the rpm package file using a method as described in
    section 3) of this security announcement.
    Use the command `rpm -Uhv file.rpm' to apply the update.
    In some rare cases, the older man package contains files that conflict
    with the new version. This should not be considered a problem in this
    particular case of the man packge; use the options "--nodeps --force"
    to override.

    i386 Intel Platform:

    source rpm:

    source rpm:

    source rpm:

    source rpm:

    source rpm:

    source rpm:

    Sparc Platform:

    source rpm:

    source rpm:

    AXP Alpha Platform:

    source rpm:

    source rpm:

    source rpm:

    PPC Power PC Platform:

    source rpm:

    source rpm:

    source rpm:


2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

  - netscape
    Netscape before Version 4.77 contains a bug that allows a remote attacker
    to store JavaScript code in the comment filed of GIF files that are
    contained in a viewed page. This code can be executed.
    Update packages for the SuSE Linux distributions 6.3, 6.4, 7.0 and 7.1
    can be found on our ftp server at
    The packages are gpg-signed. See the section above about downloading
    and verifying rpm packages.
    The complexity of the netscape browser suggests by nature that more
    security related problems will be found, we will not issue a dedicated
    security announcement for the netscape package any more. Security-
    inclined users may please see the future security announcements in
    section 2) for information about security related problems with the
    netscape package.

  - gpg/gnupg
    The gpg update package that can be found on our ftp server upgrade your
    installation of gpg to the version 1.0.5. We have experienced stability
    problems when the turkish locale was used.
    We recommened our users to wait for the official SuSE Security
    Announcement about gpg/gnupg before performing the upgrade since we
    expect more changes to the package.

  - pine
    Most of the supported distributions have pine update packages in the
    update area of the ftp server that update the pine package to version
    4.33. Many vulnerabilities have been found in versions before 4.33,
    and it is recommended to perform the upgrade.
    Please note that not all packages have been built yet. See the update
    directory for your distribution (like i386/update/7.0/n1) for pine-4.33

  - dqs 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). We are working on update
    packages that fix the problem.

  - samba
    Insecure temporary file handling is the cause for a new samba version
    2.0.9 that can be found as rpm packages in the n1/ directory of your
    distribution. It is recommended to install the update package if your
    users have local shell access to your samba server (this bug is not
    remotely exploitable).
    We are currently investigating some oddity in the behaviour of the
    samba package and will send a security announcement as soon as we
    have clarified the problems. The problems were present in earlier
    releases/versions of the samba package as well. By consequence, the
    installation of the update package is of low risk for the functionality
    of your system.


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
       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,
       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 --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 uninstalled 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 "" 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 .

  - 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 annoucements are sent to this list.
            To subscribe, send an email to

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

    SuSE's security contact is
    The public key is listed below.

Roman Drahtmueller <>
 -                                                                      -
| Roman Drahtmüller       //  "The best way to pay for a  |
  SuSE GmbH - Security           Phone: // lovely moment is to enjoy it."
| Nürnberg, Germany     +49-911-740530 //          - Richard Bach        |
 -                                                                      -

    The information in this advisory may be distributed or reproduced,
    provided that the advisory is not modified in any way.
    SuSE GmbH makes no warranties of any kind whatsoever with respect
    to the information contained in this security advisory.