Macromedia Shockwave Flash Malformed Header Overflow #2

From: Marc Maiffret (marcat_private)
Date: Mon Dec 16 2002 - 17:27:13 PST

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    Macromedia Shockwave Flash Malformed Header Overflow #2
    
    Release Date:
    December 16, 2002
    
    Severity:
    High (Remote Code Execution)
    
    Systems Affected:
    Macromedia Flash Player versions less than 6.0.65.0
    
    Description:
    While working on some pre-release Retina® CHAM tools, multiple exploitable
    conditions were discovered within the Shockwave Flash file format SWF
    (pronounced "SWIF").
    
    There exists a vulnerability within Macromedia's Flash software and its
    handling of malformed Flash files. Attackers can use this vulnerability to
    compromise users of Macromedia's Flash software. A corrupt file may be
    placed on a website or in some cases within an HTML email.
    
    We provided Macromedia with various corrupt Flash files, a few of which we
    verified for exploitability. Macromedia has since fixed the exploitable
    conditions as well as various other bugs that were found.
    
    The primary danger of exploiting Macromedia Flash is its extensive user base
    and portability across operating systems. Further, it is "version frozen" on
    operating system installation set-ups, so issues may linger for sometime.
    Regardless, Macromedia has fixed all of the known issues.
    
    Technical Description:
    The data header is roughly made out as:
    
    [Flash Signature][version (1)][File Length(a number of bytes too
    short)][Frame Size (malformed)][Frame Rate (malformed)][Frame Count
    (malformed)][Data]
    
    While the diagram may remain the same for this issue as in the previous
    issue (http://www.eeye.com/html/Research/Advisories/AD20020808b.html), there
    are variations in the malformed data which are very specific to this issue.
    In this case, EBP is completely controlled, so exploitation is
    straight-forward. EDI is also directly controlled as well as EDX and EDI
    which all give attackers the ability to easily exploit the vulnerable
    scenarios.
    
    Protection:
    Retina® Network Security Scanner (http://www.eeye.com/Retina) has been
    updated to identify this latest Macromedia Flash vulnerability.
    
    Vendor Status:
    Macromedia has been notified and released a patch for this vulnerability,
    available at:
    http://www.macromedia.com/v1/handlers/index.cfm?ID=23569
    
    Credit:
    Drew Copley, Research Engineer, eEye Digital Security
    
    Greetings:
    StoneFisk, the Shrug, Zonetripper, Die Liu Yu, Dror Shalev, Malware.
    
    Copyright (c) 1998-2002 eEye Digital Security
    Permission is hereby granted for the redistribution of this alert
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    permission.
    
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    NO warranties with regard to this information. In no event shall the author
    be liable for any damages whatsoever arising out of or in connection with
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    user's own risk.
    
    Feedback
    Please send suggestions, updates, and comments to:
    
    eEye Digital Security
    http://www.eEye.com
    infoat_private
    



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