Bug 84

Summary:	tgetpass should turn off echo before emitting password prompt
Product:	Sudo	Reporter:	Mark Pettit <mark>
Component:	Sudo	Assignee:	Todd C. Miller <Todd.Miller>
Status:	RESOLVED FIXED
Severity:	security
Priority:	normal
Version:	1.6.5
Hardware:	PC
OS:	FreeBSD

Description Mark Pettit 2002-06-12 21:53:28 MDT

sudo emits the password prompt before it turns off screen echo.

On heavily loaded boxes, this can cause the user's password to show up on the
screen when he/she types it.

This would fairly easily be solved by moving the term_setattr call to before the
write(output, prompt, strlen(prompt)) call.  The prompt would still be written
to the screen, AFAIK, but not until after the tty was ready to not echo any
characters typed by the user.

I have personally witnessed this happening a number of times on some of our
very heavily-loaded machines, and it ends up echoing my password to the screen,
which bothers me a bit, and is a security weakness.

Comment 1 Todd C. Miller 2002-12-13 11:19:57 MST

That sounds entirely sensible; this change will be in the next release of sudo.