iDefense Security Advisory 06.03.08
http://labs.idefense.com/intelligence/vulnerabilities/
Jun 03, 2008

I. BACKGROUND

Sun Java System Active Server Pages is a multi-platform ASP application
server. It provides provides ASP (Active Server Pages) functionality to
a web server. More information is available at the following URL.

http://www.sun.com/software/chilisoft/index.xml

II. DESCRIPTION

Remote exploitation of multiple directory traversal vulnerabilities in
Sun Microsystem's Java System Active Server Pages allows attackers to
obtain the contents of, and delete, sensitive files on the system.

Both vulnerabilities exist within ASP applications included with the
product. When accessed via the administration server, the ASP engine
does not prevent directory traversal using the "../" construct. By
supplying a specially crafted HTTP request to one of the affected ASP
applications, an attacker is able to read from arbitrary files.

One of the applications will disclose only the first and third lines of
the file. Once the application is finished processing the file, it will
delete it.

III. ANALYSIS

Exploitation allows an attacker to gain sensitive information from the
server. No authentication is required to reach the affected ASP
applications. The attacker only needs to be able to establish a session
with the administration server on TCP port 5100.

Since the server process runs with root privileges, an attacker could
obtain the contents of, or delete, any file on the system. It is
interesting to note that attempting to exploit these vulnerabilities
via the web server results in an error as shown below.

  [Fri Feb 23 18:16:49 2007] Server object, 80004005, ASP 0175~Disallowed
Path Characters~The '..' characters are not allowed in the Path parameter
for the MapPath method.

IV. DETECTION

iDefense has confirmed the existence of these vulnerabilities within
version 4.0.2 of Sun Microsystems Inc.'s Java System Active Server
Pages. Older versions are suspected to be vulnerable.

V. WORKAROUND

In order to prevent exploitation of these vulnerabilities, disable
administration server by executing the following command as the 'root'
user.

  # /opt/casp/admtool -e

Additionally, removing the affected ASP applications will prevent
exploitation of these vulnerabilities.

VI. VENDOR RESPONSE

Sun Microsystems has addressed these vulnerabilities with the release of
version 4.0.3 of Sun Java System Active Server Pages. For more
information, refer to Sun Alert 238184 at the following URL.

http://sunsolve.sun.com/search/document.do?assetkey=1-66-238184-1

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2008-2403 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

04/04/2007  Initial vendor notification
04/05/2007  Initial vendor response
06/03/2008  Coordinated public disclosure

IX. CREDIT

The discoverer of these vulnerabilities wishes to remain anonymous.

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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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