Bugtraq mailing list archives

Re: Small bug in screen-3.7.1


From: mfisher () AISTRAT COM (Matt Fisher)
Date: Mon, 15 Sep 1997 12:35:01 -0700


That has been a small problem with screen for many years, the easiest
solution is to change the SOCKDIR in config.h.in from /tmp/screens to /tmp.
 That way each user's S-userid directory will be created in the tmp
directory.  That avoids the issue of the first random user owning the
screens directory and since /tmp has the sticky bit set you don't have to
worry about a user deleting another users screen directory.

Matt

---
Matt Fisher <mfisher () aistrat com> - http://mfisher.ml.org/~mfisher/
PH# 425-803-3213 - Fax# 425-803-9084

On Monday, September 15, 1997 11:11 AM, gershwin [SMTP:gershwin () ORCI COM]
wrote:
Sorry if this is old news, but I have not seen anything about it.
I have noticed a small bug in screen-3.7.1 when it is run un suid
When a system is rebooted the /tmp/screens directory is removed, the
first
time screen is run it makes /tmp/screens owned by the user that envoked
it,
*with that users umask*

bullwinkle: {1115} % ls -al /tmp
drwx------   3 gershwin  wheel       512 Sep 15 12:00 screens

The next time a user tries to run screen they will get a error message

bullwinkle: {1119} % screen
Directory '/tmp/screens' must have mode 777.

I can change /tmp/screens to 777 and other users can use it normaly.

but with a system user other than root owning the /tmp/screens directory
he/she could remove other users screens, nothing major but just annoying.

This has been tested on bsdi 2.0-3.0 and Linux

Logan Gabriel -- gershwin () orci com
If NT's the answer, you dont understand the question.



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