Bug 1339250 – CVE-2016-4446 setroubleshoot-plugins: insecure commands.getoutput use in the allow_execstack plugin

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Bug 1339250 - (CVE-2016-4446) CVE-2016-4446 setroubleshoot-plugins: insecure commands.getoutput use in the allow_execstack plugin

Summary:	CVE-2016-4446 setroubleshoot-plugins: insecure commands.getoutput use in the ...

Status:	CLOSED ERRATA

Aliases:	CVE-2016-4446

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 1348527
Blocks:	1332645
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Reported:	2016-05-24 09:17 EDT by Tomas Hoger
Modified:	2016-11-08 11:15 EST (History)
CC List:	5 users (show)

See Also:
Fixed In Version:	setroubleshoot-plugins 3.2.27.1, setroubleshoot-plugins 3.3.9.1
Doc Type:	If docs needed, set a value
Doc Text:	A shell command injection flaw was found in the way the setroubleshoot allow_execstack plugin executed external commands. A local attacker able to trigger an execstack SELinux denial could use this flaw to execute arbitrary code with root privileges.
Story Points:	---
Clone Of:
Environment:
Last Closed:	2016-06-23 06:55:45 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 Tomas Hoger 2016-05-24 09:17:49 EDT

It was discovered that the allow_execstack setroubleshoot plugin executes external commands using the commands.getoutput() without properly sanitizing untrusted inputs used as command arguments.  These inputs originated from SELinux AVC messages.  A local user could use this flaw to execute arbitrary code as root if they could trigger an SELinux execstack denial using a file with a specially crafted name.

The similar problem was reported for allow_execmod plugin too, related to the use of commands.getstatusoutput(), see bug 1339183.

Comment 1 Tomas Hoger 2016-05-24 09:17:54 EDT

Acknowledgments:

Name: Milos Malik (Red Hat)

Comment 5 Tomas Hoger 2016-05-25 08:58:22 EDT

This issue does not affect the default SELinux configuration, as the execstack is allowed by default for unconfined_t domain.  SELinux booleans allow_execstack (on Red Hat Enterprise Linux 6) or selinuxuser_execstack (on Red Hat Enterprise Linux 7) can be set to off to disallow execstack, and hence make it possible to generate execstack 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 6 Tomas Hoger 2016-06-21 07:39:15 EDT

Lifting embargo.

Comment 7 Tomas Hoger 2016-06-21 07:46:16 EDT

Created setroubleshoot-plugins tracking bugs for this issue:

Affects: fedora-all [bug 1348527]

Comment 8 Tomas Hoger 2016-06-21 16:52:55 EDT

Upstream commit:

https://github.com/fedora-selinux/setroubleshoot/commit/eaccf4c0d20a27d3df5ff6de8c9dcc80f6f40718

Comment 9 errata-xmlrpc 2016-06-21 17:25:02 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 10 errata-xmlrpc 2016-06-23 04:53:14 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

Comment 11 Fedora Update System 2016-06-23 13:52:57 EDT

setroubleshoot-plugins-3.3.5.1-1.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.

Comment 12 Fedora Update System 2016-06-23 13:53:33 EDT

setroubleshoot-3.3.9.1-1.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.

Comment 13 Fedora Update System 2016-06-29 13:19:38 EDT

setroubleshoot-3.2.27.1-1.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.

Comment 14 Fedora Update System 2016-06-29 13:22:00 EDT

setroubleshoot-3.3.9.1-1.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.

Comment 15 Fedora Update System 2016-07-02 15:31:57 EDT

setroubleshoot-plugins-3.3.5.1-1.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.

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