This document lists the Mitigation Options and their purpose in the Settings screen when you create a New Enhanced Mitigation Action.
Data Execute Prevention (DEP)
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Prevents attackers from using application code outside the areas of memory that are not explicitly marked as executable. DEP is a critical part of the broader set of exploit mitigation technologies developed by Microsoft such as ASLR, SeHOP, SafeSEH, and /GS. These mitigation technologies complement one another; for example, DEP’s weaknesses tend to be offset by ASLR and vice versa. DEP and ASLR used together are very difficult to bypass.
Structured Exception Handler Overwrite Protection (SEHOP)
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Prevents attackers from making use of the Structured Exception Handler (SEH) overwrite exploitation technique. SEH overwrites are commonly used by exploits that target the increasing number of browser-based vulnerabilities. The SEHOP mitigation technique is made possible because of an implicit side effect of an SEH overwrite. When the majority of stack-based buffer overflows occur, an attacker will implicitly overwrite the next pointer of an exception registration record prior to overwriting the record’s exception handler function pointer. Because the next pointer is corrupted, the integrity of the exception handler chain is broken. This insight, in combination with ASLR, is what allows SEHOP to effectively mitigate SEH overwrites. For more information about SEHOP, go to the Microsoft TechNet Blogs at http://blogs.technet.com/b/srd/archive/2009/02/02/preventing-the-exploitation-of-seh-overwrites-with-sehop.aspx.
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