Bug 248059

Summary:	CVE-2007-3102 audit logging of failed logins
Product:	Red Hat Enterprise Linux 5	Reporter:	Tomas Mraz <tmraz>
Component:	openssh	Assignee:	Tomas Mraz <tmraz>
Status:	CLOSED ERRATA	QA Contact:	Brian Brock <bbrock>
Severity:	low	Docs Contact:
Priority:	low
Version:	5.0	CC:	mmarcini, security-response-team, sgrubb
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	RHSA-2007-0540	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2007-11-07 15:32:46 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 Tomas Mraz 2007-07-12 21:03:30 UTC

+++ This bug was initially created as a clone of Bug #247797 +++

Description of problem:
The logging of failed logins can be used to inject bad information into audit
logs. Example:

ssh -l "fakeuser auid=1234 tty=pty1 host=127.0.0.1" victim

causes:

type=USER_AUTH msg=audit(06/07/2007 11:04:14.429:101) : user pid=8151 uid=root
auid=unset subj=system_u:system_r:sshd_t:s0-s0:c0.c1023 msg='PAM: authentication
acct=fakeuser auid=unknown(1234) tty=pty1 host=127.0.0.1 : exe=/usr/sbin/sshd
(hostname=discovery.redhat.com, addr=192.168.1.171, terminal=ssh res=failed)'


Version-Release number of selected component (if applicable):
all recent versions

-- Additional comment from sgrubb on 2007-06-08 15:10 EST --
ssh -l "fakeuser auid=1234 terminal=pty1 hostname=127.0.0.1" victim

Is a better test case. Using it, you can subvert ausearch and aureport when they
search or report on tty or hostname. This is important in that some people could
construct protective measures based on the audit log information and wind up
suspecting the wrong host. Its easy to image this become a DoS vector. And it
would possibly make people lose confidence in audit system.


-- Additional comment from mjc on 2007-06-15 09:19 EST --
This issue has security implications as a third party may rely on parsing the
audit logs (like a IDS/IPS system) and this false information may be able to
fool it. allocated CVE-2007-3102

The openssh package also creates USER_LOGIN audit records which have the same
log injection problem. The user name must be escaped in these audit records as well.

Comment 1 Steve Grubb 2007-07-12 21:09:29 UTC

This should be fixed as it can mislead the audit system and any analytical tools
reading the events.

Comment 7 Mark J. Cox 2007-11-07 14:19:21 UTC

removing embargo

Comment 8 errata-xmlrpc 2007-11-07 15:32:46 UTC

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2007-0540.html