Bug 964 – sudo -S does not read password from stdin

Bug 964 - sudo -S does not read password from stdin


Summary:	sudo -S does not read password from stdin

Status:	RESOLVED WORKSFORME

Product:	Sudo
Classification:	Unclassified
Component:	Sudo
Version:	1.9.5
Hardware:	PC Linux

Importance:	low normal
Assigned To:	Todd C. Miller

URL:

Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2021-02-11 06:33 MST by buzo
Modified:	2021-02-12 05:35 MST (History)
CC List:	0 users

See Also:

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Description buzo 2021-02-11 06:33:22 MST

«sudo -S» does not read the password from stdin any more. Instead, the -S is completely ignored and the regular password input happens, if connected to a terminal. If not, these two lines are printed:

sudo: no password was provided
sudo: a password is required

This is a regression in 1.9.5p2. It used to work till 1.9.5p1.

Comment 1 Todd C. Miller 2021-02-11 08:39:59 MST

I'm unable to reproduce your problem and there weren't any changes between 1.9.5p1 and 1.9.5p2 that would explain it.  Here's what I see with 1.9.5p2 on Ubuntu 20.04.2:

$ echo test123 | sudo -Sk id
[sudo] password for testuser: 
uid=0(root) gid=0(root) groups=0(root)

And here it is with no tty:

$ tty
not a tty
$ echo test123 | sudo -Sk id
[sudo] password for testuser: 
uid=0(root) gid=0(root) groups=0(root)

Are you using pre-built packages or did you compile sudo yourself?

Comment 2 buzo 2021-02-12 05:35:38 MST

Sorry for wasting your time, it was a bug in my script, not in sudo. I somehow managed to call ssh with the -n option, which obviously does not let the password through to sudo. :(