Bug 1550122 (CVE-2018-1063)

Summary:	CVE-2018-1063 policycoreutils: Relabelling of symbolic links in /tmp and /var/tmp change the context of their target instead
Product:	[Other] Security Response	Reporter:	Richard Maciel Costa <rcosta>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	dwalsh, lvrabec, mgrepl, mmalik, plautrba, pmoore, psampaio, rmetrich, security-response-team, ssekidde, vmojzis
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	Context relabeling of filesystems is vulnerable to symbolic link attack, allowing a local, unprivileged malicious entity to change the SELinux context of an arbitrary file to a context with few restrictions. This only happens when the relabeling process is done, usually when taking SELinux state from disabled to enable (permissive or enforcing).	Story Points:	---
Clone Of:		Environment:
Last Closed:	2018-03-02 16:30:12 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:
Bug Blocks:	1498774, 1545726

Description Richard Maciel Costa 2018-02-28 14:44:16 UTC

policycoreutils was found to be vulnerable to a symlink attack that allows an local user to change the SELinux context of arbitrary files. This issue only occurs at relabeling time, through symlinks present in the /tmp and /var/tmp directories.

Comment 1 Richard Maciel Costa 2018-02-28 14:44:19 UTC

Mitigation:

Remove any symbolic links from /tmp and /var/tmp directories before relabeling the file system.

Comment 6 Richard Maciel Costa 2018-03-01 15:09:30 UTC

Acknowledgments:

Name: Renaud Métrich (Red Hat)

Comment 10 errata-xmlrpc 2018-04-10 08:34:30 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2018:0913 https://access.redhat.com/errata/RHSA-2018:0913