Public Vulnerability Reports

Sun Java Runtine Environment (JRE) GIF Decoding Heap Corruption Vulnerability

03.26.09

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

DESCRIPTION

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

Values from the GIF file are used to calculate an offset to store data in a dynamic heap buffer. These values are not validated before use, which allows an attacker to store controlled data outside of the bounds of the allocated buffer. This leads to corruption of object pointers, which can be leveraged to execute arbitrary code.

ANALYSIS

Exploitation of this vulnerability results in the execution of arbitrary code with the privileges of the user viewing the web page. To exploit this vulnerability, a targeted user must load a malicious webpage created by an attacker. An attacker typically accomplishes this via social engineering or injecting content into compromised, trusted sites. After the user visits the malicious web page, no further user interaction is needed.

Since the attacker has the ability to use Java code to carefully sculpt the layout of the heap, this vulnerability can be reliably exploited.

DETECTION

iDefense has confirmed the existence of this vulnerability in Java JRE version 1.6_11. Previous versions 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 

Note: JDK and JRE 5.0, SDK and JRE 1.4.2 and 1.3.1 are not affected.

WORKAROUND

iDefense is currently unaware of any workarounds for this issue. The vulnerability occurs in a core library used by JRE, so it is not possible to disable the code.

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

CVE INFORMATION

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

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

CREDIT

This vulnerability was reported to iDefense by regenrecht.

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LEGAL NOTICES

Copyright © 2009 Verisign, Inc.

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