[Full-Disclosure] iDEFENSE Security Advisory 06.10.04: Real Networks RealPlayer URL Parsing Buffer Overflow Vulnerability

idlabs-advisories_at_idefense.com
Date: 06/11/04

  • Next message: Kurt Lieber: "[Full-Disclosure] [ GLSA 200406-07 ] Subversion: Remote heap overflow" 
    To: <idlabs-advisories@idefense.com>
Date: Thu, 10 Jun 2004 18:19:33 -0400

    Real Networks RealPlayer URL Parsing Buffer Overflow Vulnerability

    iDEFENSE Security Advisory 06.10.04
    www.idefense.com/application/poi/display?id=109&type=vulnerabilities
    June 10, 2004

    I. BACKGROUND

    RealPlayer is an application for playing various media formats,
    developed by RealNetworks Inc. For more information, visit
    http://www.real.com/

    II. DESCRIPTION

    Remote exploitation of a buffer overflow in Version 10 of Real Networks'
    RealPlayer could allow execution of arbitrary commands.

    The vulnerability specifically exists in the handling of URLs with a
    large number of period (".") characters. By creating a specially crafted
    filename, it is possible to cause the execution of arbitrary code with
    the permissions of the user that attempts to access it.

    III. ANALYSIS

    One method of exploiting this vulnerability is to place a .RAM file
    (RealPlayer Presentation) containing a maliciously constructed URL on a
    web server and send an e-mail to the target with a link containing the
    file.

    It appears the vulnerability results from allocating an array of a fixed
    size and then iterating through the URL looking for periods. As each one
    is found, a pointer to it is stored in the array, and the current index
    is incremented. No check seems to be done for writes to addresses
    outside the array.

    IV. DETECTION

    RealNetworks' RealPlayer 10 is confirmed vulnerable. Previous versions
    of RealPlayer are also suspected to be vulnerable.

    V. WORKAROUND

    iDEFENSE is currently unaware of any effective workarounds for this
    vulnerability.

    User awareness is the best defense against this class of attack. Users
    should be aware of the existence of such attacks and proceed with
    caution when following links from suspicious and/or unsolicited e-mail.

    VI. VENDOR RESPONSE

    Real Networks recommends updating affected applications to the latest
    version. Instructions for upgrading are contained in the vendor's
    security advisory located at:

    http://service.real.com/help/faq/security/040610_player/EN/

    VII. CVE INFORMATION

    A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
    been assigned yet.

    VIII. DISCLOSURE TIMELINE

    04/14/2004 Exploit discovered by iDEFENSE
    05/12/2004 Initial vendor notification
    05/12/2004 iDEFENSE clients notified
    05/13/2004 Vendor response
    06/10/2004 Coordinated public disclosure

    IX. CREDIT

    Greg MacManus (iDEFENSE Labs) is credited with this discovery.

    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

  • Next message: Kurt Lieber: "[Full-Disclosure] [ GLSA 200406-07 ] Subversion: Remote heap overflow"