CVE-2016-6197

kernel: overlayfs: missing upper dentry verification before unlink and rename

Severity Score

5.5

*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

fs/overlayfs/dir.c in the OverlayFS filesystem implementation in the Linux kernel before 4.6 does not properly verify the upper dentry before proceeding with unlink and rename system-call processing, which allows local users to cause a denial of service (system crash) via a rename system call that specifies a self-hardlink.

fs/overlayfs/dir.c en la implementación del sistema de archivos OverlayFS en el kernel de Linux en versiones anteriores a 4.6 no verifica adecuadamente la dentry superior antes de proceder con el procesamiento de desconexión y cambio de nombre de llamadas al sistema, lo que permite a usuarios locales provocar una denegación del servicio (caída de sistema) a través de una llamada al sistema cambiada de nombre que especifica un self-hardlink.

It was found that the unlink and rename functionality in overlayfs did not verify the upper dentry for staleness. A local, unprivileged user could use the rename syscall on overlayfs on top of xfs to panic or crash the system.

*Credits: N/A

CVSS Scores

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Local

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Complete

Attack Vector

Local

Attack Complexity

Medium

Authentication

None

Confidentiality

None

Integrity

None

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2016-07-11 CVE Reserved
2016-08-06 CVE Published
2023-03-08 EPSS Updated
2024-08-06 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-20: Improper Input Validation
CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CAPEC

References (15)

URL	Tag	Source
http://www.openwall.com/lists/oss-security/2016/07/11/8	Mailing List
http://www.oracle.com/technetwork/topics/security/linuxbulletinjul2016-3090544.html	Third Party Advisory
http://www.securityfocus.com/bid/91709	Vdb Entry
http://www.securitytracker.com/id/1036273	Vdb Entry

URL	Date	SRC

URL	Date	SRC
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=11f3710417d026ea2f4fcf362d866342c5274185	2019-12-27
https://github.com/torvalds/linux/commit/11f3710417d026ea2f4fcf362d866342c5274185	2019-12-27

URL	Date	SRC
http://rhn.redhat.com/errata/RHSA-2016-1847.html	2019-12-27
http://rhn.redhat.com/errata/RHSA-2016-1875.html	2019-12-27
http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html	2019-12-27
http://www.ubuntu.com/usn/USN-3070-1	2019-12-27
http://www.ubuntu.com/usn/USN-3070-2	2019-12-27
http://www.ubuntu.com/usn/USN-3070-3	2019-12-27
http://www.ubuntu.com/usn/USN-3070-4	2019-12-27
https://bugzilla.redhat.com/show_bug.cgi?id=1355650	2016-09-15
https://access.redhat.com/security/cve/CVE-2016-6197	2016-09-15

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Oracle Search vendor "Oracle"		Linux Search vendor "Oracle" for product "Linux"				6 Search vendor "Oracle" for product "Linux" and version "6"		-		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				<= 4.5.7 Search vendor "Linux" for product "Linux Kernel" and version " <= 4.5.7"		-		Affected
Oracle Search vendor "Oracle"		Vm Server Search vendor "Oracle" for product "Vm Server"				3.4 Search vendor "Oracle" for product "Vm Server" and version "3.4"		-		Affected