iDefense Security Advisory 02.12.08
http://labs.idefense.com/intelligence/vulnerabilities/
Feb 12, 2008

I. BACKGROUND

Adobe Flash Media Server is an application server for Flash based
applications. It provides an environment to run interactive media
applications, as well as audio and video streaming functionality. More
information can be found at the vendor's web site at the following URL.

http://www.adobe.com/products/flashmediaserver/

II. DESCRIPTION

Remote exploitation of multiple integer overflow vulnerabilities in
Adobe Systems Inc.'s Flash Media Server 2 could allow an
unauthenticated attacker to execute arbitrary code with SYSTEM
privileges.

The Flash Media Server contains a component called the Edge server,
which listens on TCP ports 1935 and 19350 for incoming connections.
This port is the primary port used for client/server communication. The
Edge server speaks the Real Time Message Protocol, or RTMP, a
proprietary binary protocol developed by Adobe.

These vulnerabilities exist within the code responsible for parsing RTMP
messages. In each case, a 32-bit value taken directly from the packet is
used in an arithmetic operation to calculate the number of bytes to
allocate for a dynamic buffer. This operation can overflow, which later
leads to a heap overflow.

III. ANALYSIS

Exploitation of these vulnerabilities results in the execution of
arbitrary code with SYSTEM level privileges. In order to exploit these
vulnerabilities, an attacker only needs the ability to connect to the
target server on TCP port 1935 or 19350.

Unsuccessful attempts at exploitation will likely result in the Edge
server crashing. After crashing, the Edge server will be restarted
automatically. This gives an attacker an unlimited number of attempts
at exploitation.

IV. DETECTION

iDefense has confirmed the existence of these vulnerabilities in Flash
Media Server 2 version 2.0.4 on Windows. Previous versions, as well as
the Linux version, may also be affected.

V. WORKAROUND

iDefense is currently unaware of any workarounds for this issue.

VI. VENDOR RESPONSE

Adobe has addressed these vulnerabilities by releasing version 2.0.5 of
Flash Media Server. For more information, consult their bulletin at the
following URL.

http://www.adobe.com/support/security/bulletins/apsb08-03.html

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2007-6149 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

11/27/2007  Initial vendor notification
11/27/2007  Initial vendor response
02/12/2008  Coordinated public disclosure

IX. CREDIT

These vulnerabilities were reported to VeriSign iDefense by Sebastian
Apelt.

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X. LEGAL NOTICES

Copyright © 2008 iDefense, Inc.

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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.
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