Bug 1300594 (CVE-2016-1572)

Summary:	CVE-2016-1572 ecryptfs-utils: privilege escalation by mounting over /proc/$pid
Product:	[Other] Security Response	Reporter:	Andrej Nemec <anemec>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	cbuissar, esandeen, mhlavink
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-02-23 16:54:14 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:	1300595
Bug Blocks:	1300590

Description Andrej Nemec 2016-01-21 09:15:50 UTC

An unprivileged user can mount an ecryptfs over /proc/$pid because according to stat(), it is a normal directory and owned by the user. However, the user is not actually permitted to create arbitrary directory entries in /proc/$pid, and ecryptfs' behavior might be enabling privilege escalation attacks with the help of other programs that use procfs.

Upstream bug report with reproducer:

https://bugs.launchpad.net/ecryptfs/+bug/1530566

Proposed upstream patch:

https://bazaar.launchpad.net/~ecryptfs/ecryptfs/trunk/revision/870

Comment 1 Andrej Nemec 2016-01-21 09:16:14 UTC

Created ecryptfs-utils tracking bugs for this issue:

Affects: fedora-all [bug 1300595]