Sun Java System Web Proxy Multiple Buffer Overflow Vulnerabilities

iDefense Security Advisory 05.25.07
http://labs.idefense.com/intelligence/vulnerabilities/
May 25, 2007

I. BACKGROUND

Sun Microsystems Inc's Java System is a collection of server
applications bundled together. One such server application included is
the Web Proxy Server. This software implements proxy services including
HTTP and SOCKSv5. For more information, visit the following URL.

http://www.sun.com/software/products/web_proxy/home_web_proxy.xml

II. DESCRIPTION

Remote exploitation of multiple stack-based buffer overflows in Sun
Microsystems Inc's Java System Web Proxy allows unauthenticated
attackers to execute arbitrary code with superuser privileges.

The problem specifically exists within the "sockd" daemon. This daemon
implements SOCKS proxy support for the Web Proxy product. Attackers can
cause a buffer overflow by manipulating certain bytes during protocol
negotiation.

III. ANALYSIS

Exploitation allows attackers to execute arbitrary code with the
privileges of the user running "sockd", typically root.

No authentication is required to trigger this vulnerability. The
attacker only needs the ability to open a session with the SOCKS
server.

The server runs under a watchdog process which will restart the server
in cases when it will fail. This allows attackers to repeatedly attempt
to exploit the issue.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability using version
4.0.3 of Sun Java Web Proxy Server. Lab tests were performed on an x86
RedHat enterprise Linux machine. Previous versions, including products
released under the "Sun ONE" product line, are suspected to be
vulnerable.

V. WORKAROUND

Disabling the SOCKS proxy server will prevent exploitation of this
vulnerability. Additionally, employing firewalls to limit access to the
affected service will prevent untrusted users from exploiting this
vulnerability.

VI. VENDOR RESPONSE

Sun Microsystems has addressed these vulnerabilities in Sun Alert ID
102927. For more information visit the following URL.

http://sunsolve.sun.com/search/document.do?assetkey=1-26-102927-1

VII. CVE INFORMATION

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

VIII. DISCLOSURE TIMELINE

03/20/2007  Initial vendor notification
03/22/2007  Initial vendor response
05/25/2007  Coordinated public disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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X. LEGAL NOTICES

Copyright © 2007 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
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