Bug 646386

Summary:	lnewusers can corrupt /etc/passwd
Product:	Red Hat Enterprise Linux 5	Reporter:	Miroslav Vadkerti <mvadkert>
Component:	libuser	Assignee:	Miloslav Trmač <mitr>
Status:	CLOSED NOTABUG	QA Contact:	BaseOS QE Security Team <qe-baseos-security>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	5.6	CC:	mmalik
Target Milestone:	rc
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	454892	Environment:
Last Closed:	2010-10-25 17:48:03 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:
Bug Depends On:	454892
Bug Blocks:

Description Miroslav Vadkerti 2010-10-25 09:44:02 UTC

+++ This bug was initially created as a clone of Bug #454892 +++

From Bugzilla Helper:
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Description of problem:
lnewusers doesn't check the input line if it contains too many ':' characters

Version-Release number of selected component (if applicable):
libuser-0.56.6-2

How reproducible:
Always


Steps to Reproduce:
1. lnewusers
2. write following string, press enter, press CTRL+D
testuser:password:543:543:test:user:/home/testuser:/bin/bash
3. you should see an error message like this:
Error creating home directory for testuser: couldn't determine security context for `user': No such file or directory
4. grep testuser /etc/passwd
testuser:x:543:543:test:user:/home/testuser:/bin/bash:/bin/bash

Actual Results:
lnewusers accepts line with too many ':' characters

Expected Results:
lnewusers rejects line with too many ':' characters

Additional info:

--- Additional comment from mmalik on 2008-07-16 09:19:59 EDT ---

RHTS test for this bug is available
(/CoreOS/libuser/Regression/bz454892-lnewusers-corrupt-etc-passwd ). 

--- Additional comment from mitr on 2008-07-23 09:42:05 EDT ---

Thanks for your report.

I believe this is actually correct behavior: libc's getpwent() doesn't reject
pw_shell values that contain ':', only the first 6 ':' characters serve as field
separators.

It's somewhat counter-intuitive, but it is in principle possible that somebody's
shell path contains a ':', and lnewusers should not reject lines that come from
a working /etc/passwd.

Comment 1 Miloslav Trmač 2010-10-25 17:48:03 UTC

See above:

> I believe this is actually correct behavior: libc's getpwent() doesn't reject
> pw_shell values that contain ':', only the first 6 ':' characters serve as
> field separators.

> It's somewhat counter-intuitive, but it is in principle possible that somebody's
> shell path contains a ':', and lnewusers should not reject lines that come from
> a working /etc/passwd.