Rule:

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Sid:
17560

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Summary:
This event is generated when an attempt is made to exploit a known vulnerability in an ActiveX control.

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Impact:
A successful attack can cause a buffer overflow and the subsequent execution of arbitrary code with system level privileges on a vulnerable host.

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Detailed Information:
A vulnerability exists in the way that Internet Explorer handles ActiveX controls that may present an attacker with the opportunity to run code of their choosing on a host.

In particular, this event is generated when a call to the office is made. This may indicate an attempt to exploit known vulnerabilities in that ActiveX control which may lead to a system compromise.

Microsoft Office Word 2000 SP3, 2002 SP3, 2003 SP3, and 2007 Gold and SP1; Word Viewer 2003 Gold and SP3; Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats Gold and SP1; Office 2004 and 2008 for Mac; and Open XML File Format Converter for Mac allow remote attackers to execute arbitrary code via a crafted Word document that contains a malformed value, which triggers memory corruption, aka "Word Memory Corruption Vulnerability."

NOTE: For this detection to work comprehensively, the flow depth setting in the HTTP Inspect preprocessor must be set to 0

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Affected Systems:
Microsoft Windows systems using the office ActiveX control

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Attack Scenarios:
Many types of buffer overflow exist, this is a generic term that may apply to many circumstances that result in an overflow of some kind. A parameter overflow for example, means that the attacker is able to supply data as a parameter to the execution of a program. When the program expands the supplied data, if the size of the parameter is not correctly checked, it may exceed a set limit allowing the attacker to overflow the buffer and write data into memory.
In a stack overflow, the attacker has the opportunity to overwrite a return memory address which allows them to point the return address to a memory location containing code they wish to execute. This allows the attacker to run code with the full privileges of the program in use. The attacker may also supply the address for a known important call, for example the system() call, with the arguments to the call on the stack. The stack also contains the stack pointer and the frame pointer, overwriting these values may lead to a write-what-where condition.
In a heap overflow, it is possible to overwrite function pointers that may be in memory. This may allow the attacker to execute code in memory by changing the function pointer to move to code of their choosing. This can occur even in programs that do not necessarily use function pointers since they may be left in memory at run time. The heap also contains user data which also becomes visible to the attacker.

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Ease of Attack:
Simple.

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False Positives:
None known.

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False Negatives:
None known.

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Corrective Action:
Upgrade to the most current non-affected version of the product.

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Contributors:
This document was generated from data supplied by the National Vulnerability Database. A product of the National Institute of Standards and Technology.
For more information see http://nvd.nist.gov/
Sourcefire Vulnerability Research Team
Alex Kirk <akirk@sourcefire.com>
Nigel Houghton <nigel.houghton@sourcefire.com>

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Additional References

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