SuSE: cyrus-imapd buffer overflows
Posted by Benjamin D. Thomas   
SuSE This update fixes one-byte buffer overruns in the cyrus-imapd IMAP server package.

                        SUSE Security Announcement

        Package:                cyrus-imapd
        Announcement-ID:        SUSE-SA:2005:009
        Date:                   Thu, 24 Feb 2005 14:00:00 +0000
        Affected products:      8.2, 9.0, 9.1, 9.2
                                SUSE Linux Enterprise Server 8, 9
        Vulnerability Type:     remote code execution
        Severity (1-10):        7
        SUSE default package:   yes
        Cross References:       None.

    Content of this advisory:
        1) security vulnerability resolved:
             several 1 byte buffer overflows fixed
        2) solution/workaround
        3) special instructions and notes
        4) package location and checksums
        5) pending vulnerabilities, solutions, workarounds:
             See SUSE Security Summary Report.
        6) standard appendix (further information)


1) problem description, brief discussion

    This update fixes one-byte buffer overruns in the cyrus-imapd IMAP
    server package.

    Several overruns were fixed in the IMAP annote extension as well as
    in cached header handling which can be run by an authenticated user.

    Additionally bounds checking in fetchnews was improved to avoid
    exploitation by a peer news admin.

    Please note that one-byte buffer overflows can not be exploited to
    execute arbitrary commands by manipulating the saved registers on
    the stack if the compiler used (gcc >= 3) aligns the stack space.

    Nevertheless the code behavior may be manipulated by overwriting
    local variables. The result is not known but ranges between a
    denial-of-service condition and privilege escalation.

    This update backports bugfixes from the upstream release of
    cyrus-imapd 2.2.11 announced on:

2) solution/workaround

    Install the updated packages.
    Make sure you restart cyrus-imapd by running
            /sbin/rccyrus try-restart

3) special instructions and notes


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 9.2:
    SUSE Linux 9.1:
    SUSE Linux 9.0:
    SUSE Linux 8.2:
    x86-64 Platform:
    SUSE Linux 9.2:
    source rpm(s):
    SUSE Linux 9.1:
    source rpm(s):
    SUSE Linux 9.0:
    source rpm(s):


5)  Pending vulnerabilities in SUSE Distributions and Workarounds:

    See SUSE Security Summary Report.


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
       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 -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.
        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 top-level 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 announcements are sent to this list.
            To subscribe, send an email to

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

    SUSE's security contact is  or .>.
    The  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.