Data Execution Prevention, more commonly known as DEP, was first introduced in Windows XP Service Pack 2. As its name suggests, DEP is intended to prevent applications from executing code in non-executable regions of memory. DEP raises an exception if it detects executable code loading from the default heap or stack. Since this behavior is indicative of malicious code (legitimate code does not generally load in this manner), DEP protects the browser against attacks rendered, for example, via buffer overflow and similar type vulnerabilities.
Depending on the processor, hardware or software enforced DEP can be implemented on supported operating systems. To enable DEP for Internet Explorer 6 or 7, see:
Internet Explorer 8 has hardware-enforced DEP enabled by default only on the following platforms:
- Internet Explorer 8 on Windows XP Service Pack 3
- Internet Explorer 8 on Windows Vista Service Pack 1 and higher
- Internet Explorer 8 on Windows Server 2008
- Internet Explorer 8 on Windows 7