______________________________________________________________________________

                        SuSE Security Announcement

        Package:                sendmail, sendmail-tls
        Announcement-ID:        SuSE-SA:2003:023
        Date:                   Tuesday, April 1st 2003 18:45 MEST
        Affected products:      7.1, 7.2, 7.3, 8.0, 8.1, 8.2
                                SuSE Linux Database Server,
                                SuSE Linux Enterprise Server 7, 8
                                SuSE Linux Firewall on CD/Admin host
                                SuSE Linux Connectivity Server
                                SuSE Linux Office Server
        Vulnerability Type:     local/remote privilege escalation
        Severity (1-10):        7
        SuSE default package:   yes (until SuSE Linux 8.0 and SLES7)
        Cross References:        2003 CERT Advisories

    Content of this advisory:
        1) security vulnerability resolved: sendmail, sendmail-tls
           problem description, discussion, solution and upgrade information
        2) pending vulnerabilities, solutions, workarounds:
            - glibc
            - vnc
            - openssl
        3) standard appendix (further information)

______________________________________________________________________________

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

    sendmail is the most widely used mail transport agent (MTA) in the
    internet. A remotely exploitable buffer overflow has been found in all
    versions of sendmail that come with SuSE products. These versions include
    sendmail-8.11 and sendmail-8.12 releases. sendmail is the MTA subsystem
    that is installed by default on all SuSE products up to and including
    SuSE Linux 8.0 and the SuSE Linux Enterprise Server 7.

    The vulnerability was discovered by Michal Zalewski. It is not related
    to the vulnerability found by ISS in the first week of March as announced
    by SuSE Security in SuSE Security Announcement SuSE-SA:2003:013 (CERT
    Announcement ID CA-2003-07). The impact is believed to be a local root
    compromise with the possibility of a remote compromise. Even though
    the remote nature of the vulnerability is not confirmed, we believe that
    it is safe to assume that the vulnerability may be remotely exploitable.
    The nature of the flaw is a stack overflow in a function that is called
    frequently throughout the sendmail source code. The function is used for
    processing email addresses.

    There is no known workaround for this vulnerability other than using a
    different MTA. The vulnerability is triggered by an email message sent
    through the sendmail MTA subsystem. In that respect, it is different
    from commonly known bugs that occur in the context of an open TCP
    connection. By consequence, the vulnerability also exists if email
    messages get forwarded over a relay that itself does not run a vulnerable
    MTA. This specific detail and the wide distribution of sendmail in the
    internet causes this vulnerability to be considered a flaw of major
    severity. We recommend to install the update packages that are provided
    for download at the locations listed below.

    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.

    SPECIAL INSTALL INSTRUCTIONS:
    =============================    After performing the update, it is necessary to restart all running
    instances of sendmail using the command "rcsendmail restart" as root.


    Intel i386 Platform:

    SuSE-8.1:
      
      bb987c277374db2cf5ec81b7abe9a476
    patch rpm(s):
      
      f90dc4e6f63b5c4e368e5db2fe7d09be
    source rpm(s):
      
      dd838b1089f6686a1107e6d8159b1f98

    SuSE-8.0:
      
      9e6949e973085ae3b628c52cadcc2c9e
    patch rpm(s):
      
      dac55a8afcb2487b8b80549b9a4d7b38
    source rpm(s):
      
      f6e8297e885d367a73ff9010a6cbb297

    SuSE-7.3:
      
      7591a1d397e161225b4d594bcfc5bb02
      
      52c213438e8782af09a4395d402d1fea
    source rpm(s):
      
      a7b6f85673913089758f0ef0208aac6a
      
      96cbfc4f2d85bdae71196ee80a4ebbd3

    SuSE-7.2:
      
      b107d5a44b234222de7e5fcb7998c192
      
      78a987bd0a38d067a8cffd6c6003abd8
    source rpm(s):
      
      0a86a2d3158110479c44c6b8a09f2bb6
      
      acf234a4fa14d9d078df10cd774da0ce

    SuSE-7.1:
      
      abec9a5d08d89cabc662708b38cadfad
      
      36ab02484b69d9f6ac9d58b78cc0569d
    source rpm(s):
      
      e7e267fbb800277472f797f351796c6d
      
      83b8fae134f192c53fa32c2d73f8dc8c



    Sparc Platform:

    SuSE-7.3:
      
      f3a9cff90e3ac9493bcab36b11dc692c
      
      63c14d646d8046df26c2899c0886bb24
    source rpm(s):
      
      7f01e6aa454231f35f6ee50958bb6f29
      
      e9086795f386471e6b2476febb419aa0




    AXP Alpha Platform:

    SuSE-7.1:
    Limited package building resources are delaying the availiability of
    update packages for the SuSE Linux 7.1 for Alpha distribution.


    PPC Power PC Platform:

    SuSE-7.3:
      
      1dd1154f1b9ede1dc003be26919b4d23
      
      a83a7f0885deb049a5a63d8114e47af4
    source rpm(s):
      
      2a199a60d825c8d3d2a1514fb58aea59
      
      621c390fbb8c44ffb1764d369c096d3f

    SuSE-7.1:
      
      c1657f4dbc2f4967fb3ca04c17e2f1f3
      
      7f564cc83d85970cd7c0f61896c916e6
    source rpm(s):
      
      bd749453da2ff7513f09798d8b0b2e56
      
      1c347e9052b1b7dd02ae6630c56445db


______________________________________________________________________________

2)  Pending vulnerabilities in SuSE Distributions and Workarounds:

    - glibc
      SuSE Security is working on glibc updates for the RPC XDR integer overflow
      security problem in glibc. The central function of the glibc package in a
      Linux system requires extensive testing of the update packages. The update
      packages will be provided for download at the usual location and
      publically announced as soon as the testing is completed successfully.

    - vnc
      VNC (Virtual Network Computing) uses a weak cookie generation process
      which can be exploited by an attacker to bypass authentication.
      New packages are currently being tested and will be available on our
      FTP servers soon.

    - openssl
      A paper regarding remote timing attacks against OpenSSL has been
      published by researchers of the Stanford University. It is possible
      to extract the private RSA key used by services using OpenSSL by
      observing their timing behavior. Fixed packages will be available
      on our FTP servers soon.
______________________________________________________________________________

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
        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.

    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.
       Prerequisites:
        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   .


  - 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
                <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
                <suse-security-announce-subscribe@suse.com>.

    For general information or the frequently asked questions (faq)
    send mail to:
        <suse-security-info@suse.com> or
        <suse-security-faq@suse.com> respectively.

    ====================================================================    SuSE's security contact is <security@suse.com> or <security@suse.de>.
    The <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 <security@suse.de>
pub  1024D/9C800ACA 2000-10-19 SuSE Package Signing Key <build@suse.de>