Public Vulnerability Reports

Kaspersky Internet Security Suite klif.sys Heap Overflow Vulnerability



Kaspersky Internet Security Suite is a combination of Kaspersky anti-virus, anti-spam, and personal firewall in one product. For more information see the vendor's website at the following URL.


Local exploitation of a heap overflow vulnerability in Kaspersky Lab's Internet Security Suite klif.sys could allow an attacker to execute arbitrary code within kernel context.

The klif.sys driver is part of the "anti-hacker" proactive protection. As part of this defense, the driver hooks and screens various system calls, such as registry functions.

The hook function for the _NtSetValueKey() function is vulnerable to an integer overflow that leads to a kernel heap overflow. Passing a large unsigned value for the data size argument results in an arithmetic overflow when calculating the amount of memory to allocate. A copy operation into this buffer results in corruption of kernel memory.


Exploitation allows an attacker to execute code with kernel privileges.

This vulnerability lets an attacker overwrite a nearly arbitrary amount of kernel heap memory with arbitrary data. Exploitation of kernel heap based buffer overflows is both difficult and unreliable. However, there are documented methods for exploiting these types of overflows.


iDefense confirmed this vulnerability in Kaspersky Internet Security for Windows. Previous versions may also be affected.


iDefense is currently unaware of any workarounds for this issue.


Kaspersky has addressed this vulnerability within Maintenance Pack 2. More information is available from the vendor's advisory at the following URLs.


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


01/24/2007 Initial vendor notification
03/02/2007 Second vendor notification
03/05/2007 Initial vendor response
04/03/2007 Coordinated public disclosure


The discoverer of this vulnerability wishes to remain anonymous.

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Copyright © 2007 Verisign, Inc.

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