CVE-2016-6198

kernel: vfs: missing detection of hardlinks in vfs_rename() on overlayfs

Severity Score

5.5

*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

The filesystem layer in the Linux kernel before 4.5.5 proceeds with post-rename operations after an OverlayFS file is renamed to a self-hardlink, which allows local users to cause a denial of service (system crash) via a rename system call, related to fs/namei.c and fs/open.c.

La capa del sistema de archivos en el kernel de Linux en versiones anteriores a 4.5.5 procede con operaciones de cambio de nombre después de que un archivo OverlayFS es cambiado de nombre a un self-hardlink, lo que permite a usuarios locales provocar una denegación de servicio (caída de sistema) a través de una llamada al sistema, relacionado con fs/namei.c y fs/open.c.

A flaw was found that the vfs_rename() function did not detect hard links on overlayfs. A local, unprivileged user could use the rename syscall on overlayfs on top of xfs to 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
2024-08-06 First Exploit
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-284: Improper Access Control
CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CAPEC

References (16)

URL	Tag	Source
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.5.5	Release Notes
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
http://www.openwall.com/lists/oss-security/2016/07/11/8	2024-08-06

URL	Date	SRC
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=54d5ca871e72f2bb172ec9323497f01cd5091ec7	2019-12-27
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=9409e22acdfc9153f88d9b1ed2bd2a5b34d2d3ca	2019-12-27
https://github.com/torvalds/linux/commit/54d5ca871e72f2bb172ec9323497f01cd5091ec7	2019-12-27
https://github.com/torvalds/linux/commit/9409e22acdfc9153f88d9b1ed2bd2a5b34d2d3ca	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://rhn.redhat.com/errata/RHSA-2016-2574.html	2019-12-27
http://rhn.redhat.com/errata/RHSA-2016-2584.html	2019-12-27
http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html	2019-12-27
https://bugzilla.redhat.com/show_bug.cgi?id=1355654	2016-11-03
https://access.redhat.com/security/cve/CVE-2016-6198	2016-11-03

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				<= 4.5.4 Search vendor "Linux" for product "Linux Kernel" and version " <= 4.5.4"		-		Affected
Oracle Search vendor "Oracle"		Linux Search vendor "Oracle" for product "Linux"				6 Search vendor "Oracle" for product "Linux" and version "6"		-		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