iDEFENSE Security Advisory 10.24.05: SCO Unixware Setuid ppp prompt Buffer Overflow Vulnerability

From: iDEFENSE Labs (labs-no-reply_at_idefense.com)
Date: 10/25/05

  • Next message: Martin Schulze: "[SECURITY] [DSA 870-1] New sudo packages fix arbitrary command execution"
    Date: Mon, 24 Oct 2005 18:51:26 -0400
    To: <bugtraq@securityfocus.com>, <vulnwatch@vulnwatch.org>, <full-disclosure@lists.grok.org.uk>
    
    

    SCO Unixware Setuid ppp prompt Buffer Overflow Vulnerability

    iDEFENSE Security Advisory 10.24.05
    http://www.idefense.com/application/poi/display?type=vulnerabilities
    October 24, 2005

    I. BACKGROUND

    SCO UnixWare is a UNIX operating system.

    More information is available at:

      http://www.sco.com/products/unixware714/

    II. DESCRIPTION

    Local exploitation of a buffer overflow vulnerability in the ppp binary,

    as included in multiple versions of The SCO Group Inc.'s Unixware,
    allows attackers to gain root privileges.

    The vulnerability specifically exists because of a failure to check the
    length of user input. If the user running the ppp program enters an
    argument to the "prompt" or "defprompt" command that exceeds 256 bytes
    in
    length, a stack based overflow occurs. This leads to the execution of
    arbitrary code with root privileges, as ppp is setuid root by default.

    III. ANALYSIS

    Successful exploitation of this vulnerability requires that user have
    local access to the system; it would allow the user to gain superuser
    privileges.

    IV. DETECTION

    iDEFENSE has confirmed the existence of this vulnerability in SCO
    Unixware versions 7.1.3 and 7.1.4. All versions of SCO Unixware are
    suspected to be vulnerable.

    V. WORKAROUND

    As a workaround solution, remove the setuid bit from the backupsh binary

    until a vendor patch can be applied.

      # chmod u-s /usr/bin/ppp

    VI. VENDOR RESPONSE

    The vendor has released the following advisory for this issue:

      ftp://ftp.sco.com/pub/updates/UnixWare/SCOSA-2005.41/SCOSA-2005.41.txt

    VII. CVE INFORMATION

    The Common Vulnerabilities and Exposures (CVE) project has assigned the
    name CVE-2005-2927 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

    09/08/2005 Initial vendor notification
    09/09/2005 Initial vendor response
    10/24/2005 Public disclosure

    IX. CREDIT

    iDEFENSE Labs is credited with the discovery of this vulnerability.

    Get paid for vulnerability research
    http://www.idefense.com/poi/teams/vcp.jsp

    Free tools, research and upcoming events
    http://labs.idefense.com

    X. LEGAL NOTICES

    Copyright (c) 2005 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.


  • Next message: Martin Schulze: "[SECURITY] [DSA 870-1] New sudo packages fix arbitrary command execution"