Linux Kernel up to 4.8 Mount fs/namespace.c MS_BIND Mount System Calls resource consumption

CVSS Meta Temp Score
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CTI Interest Score
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3.9$0-$5k0.00

Summaryinfo

A vulnerability labeled as problematic has been found in Linux Kernel up to 4.8. This issue affects some unknown processing of the file fs/namespace.c of the component Mount Handler. The manipulation as part of MS_BIND Mount System Calls results in resource consumption. This vulnerability is reported as CVE-2016-6213. The attack requires a local approach. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 4.8 (Operating System). Affected is an unknown part of the file fs/namespace.c of the component Mount Handler. The manipulation as part of a MS_BIND Mount System Calls leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. CVE summarizes:

fs/namespace.c in the Linux kernel before 4.9 does not restrict how many mounts may exist in a mount namespace, which allows local users to cause a denial of service (memory consumption and deadlock) via MS_BIND mount system calls, as demonstrated by a loop that triggers exponential growth in the number of mounts.

The bug was discovered 07/13/2016. The weakness was disclosed 12/28/2016 as confirmed git commit (GIT Repository). The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2016-6213 since 07/13/2016. The attack needs to be approached locally. A authentication is necessary for exploitation. There are known technical details, but no exploit is available.

The vulnerability was handled as a non-public zero-day exploit for at least 160 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 95995 (Ubuntu 16.04 LTS : linux vulnerabilities (USN-3161-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Ubuntu Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 196658 (Ubuntu Security Notification for Linux Vulnerabilities (USN-3161-1)).

Upgrading to version 4.9 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (95995) and SecurityFocus (BID 91754†). The entries VDB-87607, VDB-93501, VDB-93842 and VDB-93844 are pretty similar. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.0
VulDB Meta Temp Score: 3.9

VulDB Base Score: 3.3
VulDB Temp Score: 3.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.7
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
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Exploitinginfo

Class: Resource consumption
CWE: CWE-400 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 95995
Nessus Name: Ubuntu 16.04 LTS : linux vulnerabilities (USN-3161-1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 860758
OpenVAS Name: Ubuntu Update for linux-lts-xenial USN-3161-2
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
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Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 4.9
Patch: git.kernel.org

Timelineinfo

07/13/2016 🔍
07/13/2016 +0 days 🔍
07/13/2016 +0 days 🔍
12/20/2016 +160 days 🔍
12/21/2016 +1 days 🔍
12/28/2016 +7 days 🔍
12/28/2016 +0 days 🔍
12/28/2016 +0 days 🔍
10/12/2022 +2114 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: RHSA-2017:1842
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2016-6213 (🔍)
GCVE (CVE): GCVE-0-2016-6213
GCVE (VulDB): GCVE-100-94692
SecurityFocus: 91754 - Linux Kernel CVE-2016-6213 Local Denial of Service Vulnerability

See also: 🔍

Entryinfo

Created: 12/28/2016 16:10
Updated: 10/12/2022 18:36
Changes: 12/28/2016 16:10 (79), 07/24/2019 12:18 (6), 10/12/2022 18:36 (3)
Complete: 🔍
Cache ID: 216:567:103

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