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                                  CERT-Renater

                       Note d'Information No. 2005/VULN339
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DATE                      : 27/05/2005

HARDWARE PLATFORM(S)      : /

OPERATING SYSTEM(S)       : Solaris 9, Solaris 10.

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Sun(sm) Alert Notification
      * Sun Alert ID: 57795
      * Synopsis: Security Vulnerability in the WU-FTPD "wu_fnmatch"
        Function May Result in a Denial of Service (DoS)
      * Category: Security
      * Product: Solaris
      * BugIDs: 6239487
      * Avoidance: Workaround, T-Patch
      * State: Engineering Complete
      * Date Released: 20-May-2005
      * Date Closed:
      * Date Modified: 23-May-2005

1. Impact

    The Solaris 9 and Solaris 10 FTP Server, in.ftpd(1M), is based on
    WU-FTPD (Washington University ftpd) and are affected by a security
    vulnerability in the "wu_fnmatch" function which may allow a local or
    remote unprivileged user the ability to cause a Denial of Service (DoS)
    by consuming a large amount of CPU resources.

    Additional information on this issue can be found in the following
    documents:

      * CAN-2005-0256 (see:
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-0256)
      * iDEFENSE Security Advisory 02.25.05 (see:
        http://www.idefense.com/application/poi/display?id=207&type=vulnerabilities)

2. Contributing Factors

    This issue can occur in the following releases:

    SPARC Platform

      * Solaris 9
      * Solaris 10

    x86 Platform

      * Solaris 9
      * Solaris 10

    Notes:

     1. Solaris 7 and Solaris 8 are not affected by this issue.
     2. This issue only impacts the "WU-FTPD" version of in.ftpd(1M).
     3. This issue only affects systems which are enabled as in.ftpd(1M)
        servers.

3. Symptoms

    If the described issue occurs, the CPU utilization will go up to 100%and
    the prstat(1M) command will show that the "in.ftpd" process is consuming
    a lot of CPU time.

    Symptoms similar to the following may be seen:

      * Slow running applications
      * Delayed response from the terminals
      * Slow response over the network

Solution Summary

4. Relief/Workaround

    To work around the described issue, disable ftp(1) service by doing the
    following:

    On Solaris 9

    1. Login as root.

    2. Edit the "/etc/inetd.conf" file and comment out the line starting
       with "ftp".

    3. Tell the inetd(1M) process to reread the newly modified
       "/etc/inetd.conf" file by sending it a hangup signal, SIGHUP:

       # pkill -HUP inetd

    On Solaris 10

    1. Login as root.

    2. Disable the in.ftpd(1M) server using the following command:

       # svcadm disable ftp

    Preliminary T-patches are available for the following releases from
    http://sunsolve.sun.com/tpatches:

    SPARC

      * Solaris 9 T-patch T114564-05

    x86 Platform

      * Solaris 9 T-patch T114565-05

    This document refers to one or more preliminary temporary patches
    (T-Patches) which are designed to address the concerns identified
    herein. Sun has limited experience with these patches due to their
    preliminary nature. As such, you should only install the patches on
    systems meeting the configurations described above. Sun may release
    full patches at a later date, however, Sun is under no obligation
    whatsoever to create, release, or distribute any such patch.

5. Resolution

    A final resolution is pending completion.

    Change History 23-May-2005:

      * Updated Relief/Workaround Section

    This Sun Alert notification is being provided to you on an "AS IS"
    basis. This Sun Alert notification may contain information provided by
    third parties. The issues described in this Sun Alert notification may
    or may not impact your system(s). Sun makes no representations,
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    Copyright 2000-2005 Sun Microsystems, Inc., 4150 Network Circle, Santa
    Clara, CA 95054 U.S.A. All rights reserved.

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