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There used to be a weird trick here: Who says drive letters have to be letters? If you had more than 26 drives, msdos just took whatever was in the ascii table

There used to be a weird trick here: Who says drive letters have to be letters? If you had more than 26 drives, msdos just took whatever was in the ascii table after Z: . This was easy to cause with network drives. Programs mostly just went with it unquestioningly. I don 't remember what happens if your drive letter itself is a backslash. A few years ago it was still possible to do stuff like subst ?: C:\somepath Then you had a drive ?: which was accepted by half of your programs but not the others. I don't have a win10 laying around so I can't test if this is still true today.

Jaruzel 5y ago
Yes that still works under Windows 10/11. Useful if you are working in the command line, and have tools somewhere else that you are accessing (that are not in the PATH) and you get tired of typing the full path to the tools.
xmcqdpt2 5y ago
>A few years ago it was still possible to do stuff like > subst ?: C:\somepath >Then you had a drive ?: which was accepted by half of your programs but not the others. Neat! Like a Windows version of chroot? Can it be used to stop programs from accessing C?
- hyperman1 5y ago
  I don't think subst is a good idea for security purposes. You can't hide the original drive, some tools look right trough it, and UNC path names allow other ways. Windows has the concepts of window stations and sessions. One of these 2 is the namespace for drive letters, as it allows different rdp users to have their own network drives, and also give services their own security context . Take sysinternals winobj to look around. Maybe you can build something chrootlike out of it, I dont really know, I am a bit out of my depth here.
errcorrectcode 5y ago
Muhaha. As a DoS of DOS: x:\> copy c:\config.sys CLOCK$ Also special DOS filenames: CON PRN AUX NUL {COM,LPT}[1-9] https://superuser.com/questions/1362080/which-characters-are-invalid-for-an-ms-dos-filename https://superuser.com/questions/1362080/which-characters-are... Print autoexec.bat to the dot matrix printer on LPT1? x:\> copy autoexec.bat lpt1 x:\> Create a file called foo.txt without an editor? x:\> copy con foo.txt whatever whatever whatever whatever ^Z<ENTER> x:\> A social DoS of any machine with BASIC or similar. 10 INPUT "Press any key to continue..."; $X 20 GOTO 10 When good floppies go bad: General Failure reading drive A:\. Abort, Ignore, Retry, Fail?

Jaruzel 5y ago

Yes that still works under Windows 10/11. Useful if you are working in the command line, and have tools somewhere else that you are accessing (that are not in the PATH) and you get tired of typing the full path to the tools.

xmcqdpt2 5y ago

>A few years ago it was still possible to do stuff like > subst ?: C:\somepath >Then you had a drive ?: which was accepted by half of your programs but not the others. Neat! Like a Windows version of chroot? Can it be used to stop programs from accessing C?

hyperman1 5y ago
I don't think subst is a good idea for security purposes. You can't hide the original drive, some tools look right trough it, and UNC path names allow other ways. Windows has the concepts of window stations and sessions. One of these 2 is the namespace for drive letters, as it allows different rdp users to have their own network drives, and also give services their own security context . Take sysinternals winobj to look around. Maybe you can build something chrootlike out of it, I dont really know, I am a bit out of my depth here.

errcorrectcode 5y ago

Muhaha. As a DoS of DOS: x:\> copy c:\config.sys CLOCK$ Also special DOS filenames: CON PRN AUX NUL {COM,LPT}[1-9] https://superuser.com/questions/1362080/which-characters-are-invalid-for-an-ms-dos-filename https://superuser.com/questions/1362080/which-characters-are... Print autoexec.bat to the dot matrix printer on LPT1? x:\> copy autoexec.bat lpt1 x:\> Create a file called foo.txt without an editor? x:\> copy con foo.txt whatever whatever whatever whatever ^Z<ENTER> x:\> A social DoS of any machine with BASIC or similar. 10 INPUT "Press any key to continue..."; $X 20 GOTO 10 When good floppies go bad: General Failure reading drive A:\. Abort, Ignore, Retry, Fail?