what you don't know can hurt you
Home Files News &[SERVICES_TAB]About Contact Add New

iDEFENSE Security Advisory 2009-03-25.1

iDEFENSE Security Advisory 2009-03-25.1
Posted Mar 26, 2009
Authored by iDefense Labs, Sean Larsson | Site idefense.com

iDefense Security Advisory 03.25.09 - Remote exploitation of an integer signedness vulnerability in Sun Microsystems Inc.'s Java JRE could allow an attacker to execute arbitrary code with the privileges of the current user. The vulnerability exists within the font parsing code in the JRE. As part of its font API, the JRE provides the ability to load a font from a remote URL. iDefense has confirmed the existence of this vulnerability in Sun Microsystem Inc.'s Java JRE version 1.6.0_11 for Windows. Previous versions and versions for other platforms may also be affected.

tags | advisory, java, remote, arbitrary
systems | windows
SHA-256 | 3bc84907efc86fab9cc714244a3052994583300cd2f5c0cdbaf928ca680eb1b5

iDEFENSE Security Advisory 2009-03-25.1

Change Mirror Download
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

iDefense Security Advisory 03.25.09
http://labs.idefense.com/intelligence/vulnerabilities/
Mar 25, 2009

I. BACKGROUND

The Sun Java JRE is Sun's implementation of the Java runtime. For more
information, see the vendor's site found at the following link.

http://www.java.com

II. DESCRIPTION

Remote exploitation of an integer signedness vulnerability in Sun
Microsystems Inc.'s Java JRE could allow an attacker to execute
arbitrary code with the privileges of the current user.

The vulnerability exists within the font parsing code in the JRE. As
part of its font API, the JRE provides the ability to load a font from
a remote URL.

The vulnerability occurs when parsing glyph description instructions in
the font file. When parsing the glyph descriptions, a 16bit signed
counter is used as the index to store the next glyph point value. This
counter is compared to a 32bit value that represents the maximum size
of the heap buffer. Under certain conditions, the 16bit counter will be
interpreted as a negative value, which allows the attacker to store data
before the allocated buffer.

III. ANALYSIS

Exploitation allows attackers to execute arbitrary code in the context
of the currently logged-on user. To exploit this vulnerability, a
targeted user must load a malicious Web page created by an attacker. An
attacker typically accomplishes this via social engineering or injecting
content into compromised, trusted sites.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in Sun
Microsystem Inc.'s Java JRE version 1.6.0_11 for Windows. Previous
versions and versions for other platforms may also be affected.

Sun Microsystems reports that the vulnerability can occur in the
following Java SE and Java SE for Business releases for Windows,
Solaris, and Linux:

* JDK and JRE 6 Update 12 and earlier
* JDK and JRE 5.0 Update 17 and earlier

V. WORKAROUND

There is a potential workaround for the vulnerability, but it renders
the JRE unusable. It is possible to use the cacls program to change the
file permissions on fontmanager.dll. This will prevent the vulnerable
library from loading. This workaround can be applied with the following
command line:

echo y| cacls "C:\Program
Files\Java\**JRE_VERSION**\bin\fontmanager.dll" /E /P everyone:N

However, this workaround has a serious impact on the functionality of
the JRE. When a webpage attempts to load an applet, the JRE will abort
with a runtime error, and the browser will close.

VI. VENDOR RESPONSE

Sun Microsystem Inc. has released a patch which addresses this issue.
For more information, consult their advisory at the following URL:

http://sunsolve.sun.com/search/document.do?assetkey=1-66-254571-1

VII. CVE INFORMATION

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

VIII. DISCLOSURE TIMELINE

02/18/2009 - Initial Contact
02/18/2009 - PoC Requested
02/19/2009 - PoC Sent
03/10/2009 - Disclosure Date Set
03/25/2009 - Coordinated Public Disclosure

IX. CREDIT

This vulnerability was discovered by Sean Larsson, iDefense.

Get paid for vulnerability research
http://labs.idefense.com/methodology/vulnerability/vcp.php

Free tools, research and upcoming events
http://labs.idefense.com/

X. LEGAL NOTICES

Copyright © 2009 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 e-mail 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.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFJy8A1bjs6HoxIfBkRAoAHAJ9XaF14FxsjJ7UNZzhieQK0ovJmZgCgw9vz
CCcIVkotSAaGK4tT9/x/QxI=
=mc3z
-----END PGP SIGNATURE-----

Login or Register to add favorites

File Archive:

March 2024

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    Mar 1st
    16 Files
  • 2
    Mar 2nd
    0 Files
  • 3
    Mar 3rd
    0 Files
  • 4
    Mar 4th
    32 Files
  • 5
    Mar 5th
    28 Files
  • 6
    Mar 6th
    42 Files
  • 7
    Mar 7th
    17 Files
  • 8
    Mar 8th
    13 Files
  • 9
    Mar 9th
    0 Files
  • 10
    Mar 10th
    0 Files
  • 11
    Mar 11th
    15 Files
  • 12
    Mar 12th
    19 Files
  • 13
    Mar 13th
    21 Files
  • 14
    Mar 14th
    38 Files
  • 15
    Mar 15th
    15 Files
  • 16
    Mar 16th
    0 Files
  • 17
    Mar 17th
    0 Files
  • 18
    Mar 18th
    10 Files
  • 19
    Mar 19th
    32 Files
  • 20
    Mar 20th
    46 Files
  • 21
    Mar 21st
    16 Files
  • 22
    Mar 22nd
    13 Files
  • 23
    Mar 23rd
    0 Files
  • 24
    Mar 24th
    0 Files
  • 25
    Mar 25th
    12 Files
  • 26
    Mar 26th
    31 Files
  • 27
    Mar 27th
    19 Files
  • 28
    Mar 28th
    42 Files
  • 29
    Mar 29th
    0 Files
  • 30
    Mar 30th
    0 Files
  • 31
    Mar 31st
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2022 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close