Bug 1332644 – CVE-2016-4444 setroubleshoot-plugins: insecure commands.getstatusoutput use in the allow_execmod plugin

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Bug 1332644 - (CVE-2016-4444) CVE-2016-4444 setroubleshoot-plugins: insecure commands.getstatusoutput use in the allow_execmod plugin

Summary:	CVE-2016-4444 setroubleshoot-plugins: insecure commands.getstatusoutput use i...

Status:	CLOSED ERRATA

Aliases:	CVE-2016-4444

Product:	Security Response
Classification:	Other
Component:	vulnerability (Show other bugs)
Sub Component:
Version:	unspecified
Hardware:	All Linux

Priority	high Severity high
Target Milestone:	---
Target Release:	---
Assigned To:	Red Hat Product Security
QA Contact:
Docs Contact:

URL:
Whiteboard:	impact=important,public=20160621,repo...
Keywords:	Security

Depends On:	1332411 1339369 1339370 1339372
Blocks:	1332645
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Reported:	2016-05-03 11:57 EDT by Adam Mariš
Modified:	2016-06-23 06:55 EDT (History)
CC List:	5 users (show)

See Also:
Fixed In Version:	setroubleshoot-plugins 3.2.23
Doc Type:	Bug Fix
Doc Text:	A shell command injection flaw was found in the way the setroubleshoot allow_execmod plugin executed external commands. A local attacker able to trigger an execmod SELinux denial could use this flaw to execute arbitrary code with root privileges.
Story Points:	---
Clone Of:
Environment:
Last Closed:	2016-06-23 06:55:52 EDT
Type:	---
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

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External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Red Hat Product Errata	RHSA-2016:1267	normal	SHIPPED_LIVE	Important: setroubleshoot and setroubleshoot-plugins security update	2016-06-21 21:24:18 EDT
Red Hat Product Errata	RHSA-2016:1293	normal	SHIPPED_LIVE	Important: setroubleshoot and setroubleshoot-plugins security update	2016-06-23 08:52:54 EDT

Groups: None (edit)

Description Adam Mariš 2016-05-03 11:57:24 EDT

It was reported that execmod and execstack setroubleshoot plugins use commands.getstatusoutput("... %s ...") which can be misused in such a way when appropriate setroubleshoot plugin analyzes the AVC triggered by binary, setroubleshoot daemon executes arbitrary commands which are part of the binary filename.

Product bug:

https://bugzilla.redhat.com/show_bug.cgi?id=1332411

Comment 1 Adam Mariš 2016-05-03 11:57:27 EDT

Acknowledgments:

Name: Milos Malik (Red Hat)

Comment 3 Tomas Hoger 2016-05-24 06:57:26 EDT

The use of commands.getstatusoutput() was previously removed via the following commit:

https://github.com/fedora-selinux/setroubleshoot/commit/5cd60033ea7f5bdf8c19c27b23ea2d773d9b09f5

Comment 6 Tomas Hoger 2016-05-24 09:22:07 EDT

(In reply to Adam Mariš from comment #0)
> It was reported that execmod and execstack setroubleshoot plugins use
> commands.getstatusoutput("... %s ...") which can be misused ...

The allow_execstack plugin uses commands.getoutput() instead, and has not been fixed in the past as allow_execmod plugin (see comment 3).  Therefore, the allow_execstack issue needs to be handled via separate bug / CVE.  A new bug 1339250 was filed for that issue.

Comment 8 Tomas Hoger 2016-05-25 08:57:48 EDT

This issue does not affect the default SELinux configuration, as the execmod is allowed by default for unconfined_t domain.  SELinux booleans allow_execmod (on Red Hat Enterprise Linux 6) or selinuxuser_execmod (on Red Hat Enterprise Linux 7) can be set to off to disallow execmod, and hence make it possible to generate execmod AVC, which triggers this bug.

The impact of this issue on Red Hat Enterprise Linux 7.2 and later is reduced, as setroubleshootd does not run with root privileges, but with privileges of a dedicated non-root user setroubleshoot.

Comment 9 Tomas Hoger 2016-06-21 07:37:40 EDT

Lifting embargo.

Comment 10 errata-xmlrpc 2016-06-21 17:24:49 EDT

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2016:1267 https://access.redhat.com/errata/RHSA-2016:1267

Comment 11 errata-xmlrpc 2016-06-23 04:53:09 EDT

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:1293 https://access.redhat.com/errata/RHSA-2016:1293

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