NX-Bit Protects Against WMF Vuln

In this interview, Ilfak Guilfanov (author of the IDA Pro disassembler and the unofficial WMF patch) indicates that x86 systems with a per-page no-execute flag were protected from the recent WMF vulnerability.

If this is true, I hope the AMD marketing department issues a press release. This was possibly the most dangerous security threat all year, yet anyone who bought an AMD system in the past year was completely safe.

The first x86 processor with a per-page no-execute flag was the AMD Opteron. We called it the NX-Bit (and later, EVP). Subsequently, Intel implemented the execute-disable or XD-Bit (which is, of course, the exact same thing). Eventually Microsoft stepped in and further complicated clarified things by choosing the neutral moniker DEP (data execution prevention).


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