Rule

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Sid
20269

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Summary:
This event is generated when an attempt is made to exploit a known vulnerability in windows 2003 server.

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Impact:
Denial of Service. Information disclosure. Loss of integrity. 

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Detailed Information:
Buffer overflow in win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 allows remote attackers to execute arbitrary code via a crafted .fon file, aka "Font Library File Buffer Overrun Vulnerability."

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Affected Systems:
microsoft windows 2003 server 

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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. Exploits exist.

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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 latest non-affected version of the software.

Apply the appropriate vendor supplied patches.

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Contributors:
Sourcefire Vulnerability Research Team
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/

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Additional References:

NIST CVE-2011-2003:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2011-2003
 
Common Weakness Enumeration:
http://cwe.mitre.org/data/definitions/120.html
 
Common Attack Pattern Enumeration and Classification:
http://capec.mitre.org/data/definitions/100.html

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