RE: CDE libDtHelp LOGNAME Buffer Overflow Vulnerability

From: Thor Larholm (tlarholm_at_pivx.com)
Date: 08/26/04

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    Date: Thu, 26 Aug 2004 11:32:22 -0700
To: "Jrme\" ATHIAS" <jerome.athias@caramail.com>, <bugtraq@securityfocus.com>

    Hi Sunil,

    Did iDefense stop posting vulnerabilities to Bugtraq as a matter of
    policy or has it just been an error?

    I can understand the business motivations for you to restrict
    information sharing, though I might disagree.

    Regards

    Thor Larholm
    Senior Security Researcher
    PivX Solutions
    23 Corporate Plaza #280
    Newport Beach, CA 92660
    http://www.pivx.com
    thor@pivx.com
    Stock symbol: (PIVX.OB)
    Phone: +1 (949) 231-8496
    PGP: 0x4207AEE9
    B5AB D1A4 D4FD 5731 89D6 20CD 5BDB 3D99 4207 AEE9

    PivX defines a new genre in Desktop Security: Proactive Threat
    Mitigation.
    <http://www.pivx.com/qwikfix>

    -----Original Message-----
    From: Jrme" ATHIAS [mailto:jerome.athias@caramail.com]
    Sent: Wednesday, August 25, 2004 12:23 PM
    To: bugtraq@securityfocus.com
    Subject: CDE libDtHelp LOGNAME Buffer Overflow Vulnerability

    i dont know if iDEFENSE will post it out of his mailing-list. so...

    CDE libDtHelp LOGNAME Buffer Overflow Vulnerability

    iDEFENSE Security Advisory 08.25.04

    www.idefense.com/application/poi/display?id=134&type=vulnerabilities

    August 25, 2004

    I. BACKGROUND

    The libDtHelp library is a core component of the Common Desktop

    Environment (CDE). It provides the help subsystem used by most CDE

    applications.

    II. DESCRIPTION

    Exploitation of a buffer overflow in the libDtHelp library included with

    CDE can allow local attackers to gain root privileges.

    The vulnerability specifically exists due to a lack of bounds checking

    on the LOGNAME environment variable. Local attackers can specify a long

    LOGNAME to trigger a buffer overflow in any application linked with

    libDtHelp. The overflow is activated once the help subsystem is accessed

    by selecting any option under the Help menu.

    This vulnerability occurs in the same sequence of code as the previously

    disclosed DTSEARCHPATH and DTUSERSEARCHPATH vulnerabilities, described

    in CAN-2003-0834. However, the LOGNAME environment variable was not

    reported as a method of attack in related advisories.

    US-CERT Vulnerability Note VU#575804, detailing the original attack

    vectors is available at:

    http://www.kb.cert.org/vuls/id/575804

    III. ANALYSIS

    Successful exploitation leads to root level access. CDE is a widely

    deployed default desktop environment for UNIX operating systems.

    Depending on the function of the machine, this vulnerability could lead

    to exposure of highly sensitive data. The vulnerability is easily

    exploitable even when stack protections are enabled, furthering the

    impact of exposure.

    IV. DETECTION

    iDEFENSE has confirmed the existence of this vulnerability in Solaris 8

    and Solaris 9 without the patches provided for in Sun Alert 57414.

    Hewlett Packard HP-UX, Silicon Graphics, Inc. Irix and SCO Unixware are

    also reportedly vulnerable.

    V. WORKAROUND

    If possible, remove the setuid bit from all applications linked to

    libDtHelp. The command 'ldd' will display libraries linked with the

    specified executable.

    VI. VENDOR RESPONSE

    Sun successfully addressed this issue with the patches described in Sun

    Alert 57414. Specific vendor advisories addressing CAN-2003-0834 are

    available in US-CERT Vulnerability Note VU#575804

    (http://www.kb.cert.org/vuls/id/575804).

    It is believed that other

    vendor patches for CAN-2003-0834 will protect against this new attack

    vector.

    VII. CVE INFORMATION

    The Common Vulnerabilities and Exposures (CVE) project has assigned the

    name CAN-2003-0834 to this issue. This is a candidate for inclusion in

    the CVE list (http://cve.mitre.org),

    which standardizes names for

    security problems.

    VIII. DISCLOSURE TIMELINE

    03/04/2004 Initial vendor contact

                 (Opengroup.org)

    03/04/2004 iDEFENSE clients notified

    03/31/2004 Initial vendor response

                 (Opengroup.org - further coordination requested)

    04/19/2004 Initial vendor contact

                 (Hewlett-Packard, IBM, and Sun Microsystems)

    04/19/2004 Initial vendor response (Sun Microsystems)

    04/20/2004 Initial vendor response (Hewlett-Packard)

    08/25/2004 Public disclosure

    IX. CREDIT

    iDEFENSE Labs is credited with discovering this vulnerability.

    Get paid for vulnerability research

    http://www.idefense.com/poi/teams/vcp.jsp

    X. LEGAL NOTICES

    Copyright (c) 2004 iDEFENSE, Inc.

    Permission is granted for the redistribution of this alert

    electronically. It may not be edited in any way without the express

    written consent of iDEFENSE. If you wish to reprint the whole or any

    part of this alert in any other medium other than electronically, please

    email customerservice@idefense.com for permission.

    Disclaimer: The information in the advisory is believed to be accurate

    at the time of publishing based on currently available information. Use

    of the information constitutes acceptance for use in an as is condition.

    There are no warranties with regard to this information. Neither the

    author nor the publisher accepts any liability for any direct, indirect,

    or consequential loss or damage arising from use of, or reliance on,

    this information.

    _______________________________________________

    Full-Disclosure - We believe in it.

    Charter: http://lists.netsys.com/full-disclosure-charter.html

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