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: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: 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:
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]