Home page logo
/

bugtraq logo Bugtraq mailing list archives

CIAC Bulletin H-32: HP-UX ppl Core Dump Vulnerability
From: aleph1 () DFW NET (Aleph One)
Date: Mon, 24 Feb 1997 22:10:51 -0600


-----BEGIN PGP SIGNED MESSAGE-----





             __________________________________________________________

                       The U.S. Department of Energy
                    Computer Incident Advisory Capability
                           ___  __ __    _     ___
                          /       |     /_\   /
                          \___  __|__  /   \  \___
             __________________________________________________________

                             INFORMATION BULLETIN

                       HP-UX ppl Core Dump Vulnerability

February 18, 1997 22:00 GMT                                        Number H-32
______________________________________________________________________________
PROBLEM:       A vulnerability exists in the ppl(1) program.
PLATFORM:      HP-UX 9.x and 10.x
DAMAGE:        This vulnerability may allow local users to gain root
               privileges.
SOLUTION:      Until patches are available, take the steps outlined in section
               3 as soon as possible.
______________________________________________________________________________
VULNERABILITY  Exploit details involving this vulnerability have been made
ASSESSMENT:    publicly available.
______________________________________________________________________________

[ Start AUSCERT Advisory ]



===========================================================================
AA-97.07                        AUSCERT Advisory
                         HP-UX ppl core dump vulnerability
                                18 February 1997

Last Revised: --

- ----------------------------------------------------------------------------
AUSCERT has received information that a vulnerability exists in the
ppl(1) program under HP-UX 9.x and 10.x.

This vulnerability may allow local users to gain root privileges.

Exploit information involving this vulnerability has been made publicly
available.

The patches listed in HP security bulletin #00053, 13 February 1997,
"Security Vulnerability in the ppl executable", do not correct this
problem.

Currently there are no vendor patches available that address this
vulnerability.  AUSCERT recommends that sites take the steps outlined in
section 3 as soon as possible.

This advisory will be updated as more information becomes available.
- ----------------------------------------------------------------------------

1.  Description

    AUSCERT has received information that a vulnerability exists in the
    HP-UX ppl(1) program used to perform point-to-point serial networking
    using SLIP or CSLIP.

    ppl is a setuid root program.  While ppl is executing with root
    privileges, it is possible for local users to force ppl to core dump.
    As users have the ability to manipulate the location of the core, this
    vulnerability may be used to create or overwrite any file on the
    system.

    This vulnerability is known to exist in HP-UX 9.x and 10.x.

    The patches listed in HP security bulletin #00053, 13 February 1997,
    "Security Vulnerability in the ppl executable", do not correct this
    problem.  They address other security vulnerabilities.

    Exploit information involving this vulnerability has been made publicly
    available.

    The default location for ppl under HP-UX 9.x and 10.x is /usr/bin.

2.  Impact

    Local users may be able to create or overwrite arbitrary files on
    the system.  This can be leveraged to gain root privileges.

3.  Workarounds/Solution

    AUSCERT recommends that sites prevent the exploitation of the
    vulnerability in ppl by immediately applying the workaround given in
    Section 3.1.

    If the ppl functionality is required for non privileged users, AUSCERT
    recommends that access be restricted to a trusted set of users as
    given in Section 3.2.

    Currently there are no vendor patches available that address this
    vulnerability.  AUSCERT recommends that official vendor patches be
    installed when they are made available.

3..1 Remove setuid and execute permissions

    Until official vendor patches are made available, sites should remove
    the setuid root and execute permissions from ppl.  To do this,
    the following command should be run as root:

        # chmod 400 /usr/bin/ppl
        # ls -l /usr/bin/ppl
        -r--------   1 root bin        98304 Jan 24 08:13 /usr/bin/ppl

    Note that this will remove the ability for any user to run this
    program.

3.2 Restrict ppl access

    If the ppl functionality is required by a small set of trusted users,
    sites may wish to restrict the execution of ppl to that group of users.
    For example, if the Unix group "trusted" exists and contains only
    those users allowed to use the ppl functionality, the following
    commands will restrict its use:

        # chgrp trusted /usr/bin/ppl
        # chmod 4550 /usr/bin/ppl
        # ls -l /usr/bin/ppl
        -r-sr-x---   1 root trusted    98304 Jan 24 08:13 /usr/bin/ppl

    Note access to any account in the "trusted" group will allow the ppl
    package to be exploited.

4.  Previous patches

    During the installation of HP-UX patches, copies of files being
    replaced are saved in case the patches need to be backed out of.  The
    original versions of patched files are stored in the following
    locations:

        HP-UX 9.x:      /system/<PATCH-NAME>/orig/
        HP-UX 10.x:     /var/adm/sw/patch/<PATCH_NAME>/

    If patches for vulnerable programs have been previously installed,
    copies of the vulnerable programs may be available in the above
    locations.  Sites should ensure the directories have permissions
    which restrict access to the patch areas.

5.  Additional measures

    Most Unix systems ship with numerous programs which have setuid or
    setgid privileges.  Often the functionality supplied by these
    privileged programs is not required by many sites.  The large number
    of privileged programs that are shipped by default are to cater for
    all possible uses of the system.

    AUSCERT encourages sites to examine all the setuid/setgid programs
    and determine the necessity of each program.  If a program does not
    absolutely require the setuid/setgid privileges to operate (for
    example, it is only run by the root user),  the setuid/setgid
    privileges should be removed.  Furthermore, if a program is not
    required at your site, then all execute permissions should be removed.

    A sample command to find all setuid/setgid programs is (run as root):

       # find / \( -perm -4000 -o -perm -2000 \) -type f -exec ls -l {} \;

    It is AUSCERT's experience that many vulnerability are being discovered
    in setuid/setgid programs which are not necessary for the correct
    operation of most systems.  Sites can increase their security
    by removing unnecessary setuid/setgid programs.

    For example, the functionality provided by the ppl program is
    not needed by many sites.  If sites had previously disabled this
    program, they would not have been susceptible to this latest
    vulnerability.

- ----------------------------------------------------------------------------

[ End AUSCERT Advisory ]

_____________________________________________________________________________

CIAC wishes to acknowledge the contributions of AUSCERT & Hewlett-Packard for
the information contained in this bulletin.
_____________________________________________________________________________


CIAC, the Computer Incident Advisory Capability, is the computer
security incident response team for the U.S. Department of Energy
(DOE) and the emergency backup response team for the National
Institutes of Health (NIH). CIAC is located at the Lawrence Livermore
National Laboratory in Livermore, California. CIAC is also a founding
member of FIRST, the Forum of Incident Response and Security Teams, a
global organization established to foster cooperation and coordination
among computer security teams worldwide.

CIAC services are available to DOE, DOE contractors, and the NIH. CIAC
can be contacted at:
    Voice:    +1 510-422-8193
    FAX:      +1 510-423-8002
    STU-III:  +1 510-423-2604
    E-mail:   ciac () llnl gov

For emergencies and off-hour assistance, DOE, DOE contractor sites,
and the NIH may contact CIAC 24-hours a day. During off hours (5PM -
8AM PST), call the CIAC voice number 510-422-8193 and leave a message,
or call 800-759-7243 (800-SKY-PAGE) to send a Sky Page. CIAC has two
Sky Page PIN numbers, the primary PIN number, 8550070, is for the CIAC
duty person, and the secondary PIN number, 8550074 is for the CIAC
Project Leader.

Previous CIAC notices, anti-virus software, and other information are
available from the CIAC Computer Security Archive.

   World Wide Web:      http://ciac.llnl.gov/
   Anonymous FTP:       ciac.llnl.gov (128.115.19.53)
   Modem access:        +1 (510) 423-4753 (28.8K baud)
                        +1 (510) 423-3331 (28.8K baud)

CIAC has several self-subscribing mailing lists for electronic
publications:
1. CIAC-BULLETIN for Advisories, highest priority - time critical
   information and Bulletins, important computer security information;
2. CIAC-NOTES for Notes, a collection of computer security articles;
3. SPI-ANNOUNCE for official news about Security Profile Inspector
   (SPI) software updates, new features, distribution and
   availability;
4. SPI-NOTES, for discussion of problems and solutions regarding the
   use of SPI products.

Our mailing lists are managed by a public domain software package
called ListProcessor, which ignores E-mail header subject lines. To
subscribe (add yourself) to one of our mailing lists, send the
following request as the E-mail message body, substituting
CIAC-BULLETIN, CIAC-NOTES, SPI-ANNOUNCE or SPI-NOTES for list-name and
valid information for LastName FirstName and PhoneNumber when sending

E-mail to       ciac-listproc () llnl gov:
        subscribe list-name LastName, FirstName PhoneNumber
  e.g., subscribe ciac-notes OHara, Scarlett W. 404-555-1212 x36

You will receive an acknowledgment containing address, initial PIN,
and information on how to change either of them, cancel your
subscription, or get help.

PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH computing
communities receive CIAC bulletins.  If you are not part of these
communities, please contact your agency's response team to report
incidents. Your agency's team will coordinate with CIAC. The Forum of
Incident Response and Security Teams (FIRST) is a world-wide
organization. A list of FIRST member organizations and their
constituencies can be obtained via WWW at http://www.first.org/.

This document was prepared as an account of work sponsored by an
agency of the United States Government. Neither the United States
Government nor the University of California nor any of their
employees, makes any warranty, express or implied, or assumes any
legal liability or responsibility for the accuracy, completeness, or
usefulness of any information, apparatus, product, or process
disclosed, or represents that its use would not infringe privately
owned rights. Reference herein to any specific commercial products,
process, or service by trade name, trademark, manufacturer, or
otherwise, does not necessarily constitute or imply its endorsement,
recommendation or favoring by the United States Government or the
University of California. The views and opinions of authors expressed
herein do not necessarily state or reflect those of the United States
Government or the University of California, and shall not be used for
advertising or product endorsement purposes.

LAST 10 CIAC BULLETINS ISSUED (Previous bulletins available from CIAC)

H-22: talkd Buffer Overrun Vulnerability
H-23: Sendmail MIME Conversion Buffer Overrun Vulnerability
H-24: IBM AIX(r)  "gethostbyname()" Buffer Overrun Vulnerability
H-25: Vulnerability in rlogin/term
H-26: FreeBSD setlocale() Vulnerability
H-27: HP-UX vgdisplay Buffer Overrun Vulnerability
H-28: SGI IRIX startmidi/stopmidi Vulnerability
H-29: HP-UX sendmail Patches Vulnerability
H-30: Solaris ffbconfig Buffer Overrun Vulnerability
H-31: HP-UX ppl executable Vulnerability

RECENT CIAC NOTES ISSUED (Previous Notes available from CIAC)

Notes 07 - 3/29/95     A comprehensive review of SATAN

Notes 08 - 4/4/95      A Courtney update

Notes 09 - 4/24/95     More on the "Good Times" virus urban legend

Notes 10 - 6/16/95     PKZ300B Trojan, Logdaemon/FreeBSD, vulnerability
                       in S/Key, EBOLA Virus Hoax, and Caibua Virus

Notes 11 - 7/31/95     Virus Update, Hats Off to Administrators,
                       America On-Line Virus Scare, SPI 3.2.2 Released,
                       The Die_Hard Virus

Notes 12 - 9/12/95     Securely configuring Public Telnet Services, X
                       Windows, beta release of Merlin, Microsoft Word
                       Macro Viruses, Allegations of Inappropriate Data
                       Collection in Win95

Notes 96-01 - 3/18/96  Java and JavaScript Vulnerabilities, FIRST
                       Conference Announcement, Security and Web Search
                       Engines, Microsoft Word Macro Virus Update


-----BEGIN PGP SIGNATURE-----
Version: 2.6.2

iQCVAwUBMwtbSbnzJzdsy3QZAQEKSgP/aYNrrltNJb3ozopyaCLmmQJB4hYC//5w
6tmPS0Ettqhto6owStS4liHaiQ6wK9n8z/AV6RteGs+1sQSMjCvcxSWLLPgV2BlU
FRdowREsIB8CXWQQOxukFrqUstEe1tR9EIYGgt6Cp8TUSpJmnqIGyIvc33MJ33+/
koU6Qa48Bms=
=fRv/
-----END PGP SIGNATURE-----



  By Date           By Thread  

Current thread:
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]
AlienVault