Bug 2009704 (CVE-2021-3847)

Summary:	CVE-2021-3847 kernel: low-privileged user privileges escalation
Product:	[Other] Security Response	Reporter:	Marian Rehak <mrehak>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, adscvr, agk, airlied, alciregi, allarkin, bdettelb, bhu, blc, chwhite, crwood, dvlasenk, hdegoede, hkrzesin, jarod, jarodwilson, jburrell, jeremy, jforbes, jglisse, jlelli, jonathan, josef, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, mchehab, mlangsdo, nmurray, ptalbert, qzhao, rvrbovsk, steved, vkumar, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	An unauthorized access to the execution of the setuid file with capabilities flaw in the Linux kernel OverlayFS subsystem was found in the way user copying a file with capabilities from a nosuid mount into another mount. A local user could use this flaw to escalate their privileges on the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:		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:	2011439, 2011440, 2011441, 2014278
Bug Blocks:	2009706, 2009708

Description Marian Rehak 2021-10-01 11:48:36 UTC

An attacker with a low-privileged user on a Linux machine with an overlay mount which has a file capability in one of its layers may escalate his privileges up to root when copying a capable file from a nosuid mount into another mount.

Comment 7 Guilherme de Almeida Suckevicz 2021-10-14 19:32:25 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2014278]