Dailydave mailing list archives
Re: Non executable memory pages with AMD64 + XP SP2
From: Nicolas RUFF <nicolas.ruff () edelweb fr>
Date: Mon, 06 Dec 2004 16:15:51 +0100
(All in one answer) First of all, thank you everybody for your support. >[...] This means >that you hello world or basic stack overflow that you write will not >receive the protection until it is enabled system wide.I would have thought that setting "/NoExecute=AlwaysOn" in BOOT.INI should be enough to enable DEP system wide (including user apps) ... But this is not the case !
>32 bit XP SP2 does use NX technology if running on a processor that >supports it. It has to run in PAE mode though. My CPU is AMD64 Athlon 3000+ (not FX, though). It shall support NX flag. MOV EAX, 0x80000001 CPUID EAX = 00000000000000000000111101001000 (0x00000F48) EBX = 00000000000000000000000100001000 (0x00000108) EDX = 11100001110100111111101111111111 (0xE1D3FBFF) ^ |--- NX supportedI know that it should run in PAE mode for DEP to be effective, but Microsoft clearly states that PAE is enabled by default along with DEP :
http://support.microsoft.com/kb/875352 >I wrote a white paper for ISS on these shortcomings. It should be made >public pretty soon. Aaah, I feel better knowing that there is a real issue behind all this.
There should be a panel at Control Panel->Performance and Maintence->System->Advanced->Performace Settings->DEP Settings that will rewrite the boot.ini as need for whatever protection level you choose.
Yes, this parameter will set OptIn or OptOut in BOOT.INI. You won't be given a chance to select AlwaysOn or AlwaysOff or PAE through a graphical interface, though.
Regards, - Nicolas RUFF _______________________________________________ Dailydave mailing list Dailydave () lists immunitysec com https://lists.immunitysec.com/mailman/listinfo/dailydave
Current thread:
- Non executable memory pages with AMD64 + XP SP2 Nicolas RUFF (Dec 05)
- RE: Non executable memory pages with AMD64 + XP SP2 Mike Bailey (Dec 05)
- <Possible follow-ups>
- RE: Non executable memory pages with AMD64 + XP SP2 Maynor, David (ISS Atlanta) (Dec 05)
- RE: Non executable memory pages with AMD64 + XP SP2 Maynor, David (ISS Atlanta) (Dec 05)
- Re: Non executable memory pages with AMD64 + XP SP2 Nicolas RUFF (Dec 06)
- RE: Non executable memory pages with AMD64 + XP SP2 Maynor, David (ISS Atlanta) (Dec 06)