VDB-88373 · CVE-2016-4440 · OpenVAS 800972

Linux Kernel up to 4.6.3 APICv State arch/x86/kvm/vmx.c mt_rand access control

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.6	$0-$5k	0.00

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 4.6.3 (Operating System). This issue affects the function mt_rand of the file arch/x86/kvm/vmx.c of the component APICv State Handler. The manipulation of the argument https:/bugzilla.redhat.com/show_bug.cgi?id=1337806 with an unknown input leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-264. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

arch/x86/kvm/vmx.c in the Linux kernel through 4.6.3 mishandles the APICv on/off state, which allows guest OS users to obtain direct APIC MSR access on the host OS, and consequently cause a denial of service (host OS crash) or possibly execute arbitrary code on the host OS, via x2APIC mode.

The weakness was presented 05/20/2016 (oss-sec). The advisory is shared at openwall.com. The identification of this vulnerability is CVE-2016-4440 since 05/02/2016. The exploitation is known to be easy. An attack has to be approached locally. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1068 for this issue. The following code is the reason for this vulnerability:

if (enable_apicv)

The vulnerability scanner Nessus provides a plugin with the ID 92055 (Fedora 23 : kernel (2016-06f1572324)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks and running in the context l.

Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. A possible mitigation has been published 2 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (92055).

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
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VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.8
VulDB Meta Temp Score: 7.6

VulDB Base Score: 7.8
VulDB Temp Score: 7.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
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Exploitinginfo

Class: Access control
CWE: CWE-264
CAPEC: 🔍
ATT&CK: 🔍

Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	unlock	unlock	unlock	unlock
Today	unlock	unlock	unlock	unlock

Nessus ID: 92055
Nessus Name: Fedora 23 : kernel (2016-06f1572324)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 800972
OpenVAS Name: Fedora Update for kernel FEDORA-2016-06f1572324
OpenVAS File: 🔍
OpenVAS Family: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Patch: github.com

Timelineinfo

05/02/2016 🔍
05/20/2016 +18 days 🔍
06/02/2016 +13 days 🔍
06/27/2016 +25 days 🔍
06/29/2016 +2 days 🔍
07/14/2016 +15 days 🔍
08/25/2022 +2233 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: FEDORA-2016-06f1572324
Status: Not defined
Confirmation: 🔍

CVE: CVE-2016-4440 (🔍)

Entryinfo

Created: 06/29/2016 11:21 AM
Updated: 08/25/2022 12:06 PM
Changes: 06/29/2016 11:21 AM (70), 02/12/2019 10:34 AM (9), 08/25/2022 11:59 AM (4), 08/25/2022 12:06 PM (1)
Complete: 🔍
Cache ID: 98:657:40