Bug 77385

Summary:
Product:	[Retired] Red Hat Linux	Reporter:	Jan Martinek <honza>
Component:	shadow-utils	Assignee:	Nalin Dahyabhai <nalin>
Status:	CLOSED DUPLICATE	QA Contact:	David Lawrence <dkl>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	8.0	Keywords:	Security
Target Milestone:	---
Target Release:	---
Hardware:	i386
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2006-02-21 18:50:05 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Jan Martinek 2002-11-06 05:40:02 UTC

Description of Problem:

When a new user account is created by using useradd command,
a new empty mailbox is created in /var/spool/mail/newuser
with these permissions:
-rw-rw----   newuser  newgroup 
But if two (or more) users have the same GID, they can read
(and modify) each others mail. 

Version-Release number of selected component (if applicable):
shadow-utils-20000902-12

This is what I found in changelog of shadow-utils:
It probably has something to do with the problem mentioned
above.

* Wed May 23 2001 Bernhard Rosenkraenzer <bero> 20000902-1
  - Create an empty mailspool when creating a user so non-setuid/non-setgid
    MDAs (postfix+procmail) can deliver mail (#41811)

How Reproducible:

every time

Steps to Reproduce:
1. useradd -g users newuser1
2. useradd -g users newuser2
3. Now the newuser1 and newuser2 can read and modify each others mail

Actual Results:
see above

Expected Results:
Even if this is done deliberately, I would expect useradd command
to WARN about this potential security flaw.

Additional Information:

Comment 1 Mark J. Cox 2003-02-11 13:28:39 UTC


*** This bug has been marked as a duplicate of 59810 ***

Comment 2 Red Hat Bugzilla 2006-02-21 18:50:05 UTC

Changed to 'CLOSED' state since 'RESOLVED' has been deprecated.