QEMU hw/i386/kvmvapic.c patch_instruction imm32 information disclosure

CVSS Meta Temp Score
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CTI Interest Score
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7.6$0-$5k0.00

Summaryinfo

A vulnerability marked as problematic has been reported in QEMU. This affects the function patch_instruction of the file hw/i386/kvmvapic.c. The manipulation of the argument imm32 leads to information disclosure. This vulnerability is listed as CVE-2016-4020. The attack may be initiated remotely. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in QEMU (Virtualization Software) (the affected version is unknown). It has been rated as critical. This issue affects the function patch_instruction of the file hw/i386/kvmvapic.c. The manipulation of the argument imm32 with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

The patch_instruction function in hw/i386/kvmvapic.c in QEMU does not initialize the imm32 variable, which allows local guest OS administrators to obtain sensitive information from host stack memory by accessing the Task Priorty Register (TPR).

The weakness was presented 05/25/2016 by Alibaba (Website). It is possible to read the advisory at lists.gnu.org. The identification of this vulnerability is CVE-2016-4020 since 04/14/2016. The exploitation is known to be easy. Attacking locally is a requirement. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 91122 (Ubuntu 12.04 LTS / 14.04 LTS / 15.10 / 16.04 LTS : qemu, qemu-kvm vulnerabilities (USN-2974-1)), 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 176848 (Debian Security Update for qemu (DLA 1599-1)).

Upgrading eliminates this vulnerability. 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 (91122) and SecurityFocus (BID 86067†). See VDB-81088, VDB-81198, VDB-81711 and VDB-82912 for similar entries. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

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

VulDB Base Score: 9.0
VulDB Temp Score: 8.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔍

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 91122
Nessus Name: Ubuntu 12.04 LTS / 14.04 LTS / 15.10 / 16.04 LTS : qemu, qemu-kvm vulnerabilities (USN-2974-1)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 862701
OpenVAS Name: Ubuntu Update for qemu USN-2974-1
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Patch: 691a02e2ce0c413236a78dee6f2651c937b09fb0

Timelineinfo

04/13/2016 🔍
04/14/2016 +1 days 🔍
05/12/2016 +28 days 🔍
05/13/2016 +1 days 🔍
05/25/2016 +12 days 🔍
05/25/2016 +0 days 🔍
05/26/2016 +1 days 🔍
08/22/2022 +2279 days 🔍

Sourcesinfo

Product: qemu.org

Advisory: USN-2974-1
Researcher: Alibaba
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2016-4020 (🔍)
GCVE (CVE): GCVE-0-2016-4020
GCVE (VulDB): GCVE-100-87623
SecurityFocus: 86067 - QEMU CVE-2016-4020 Information Disclosure Vulnerability

See also: 🔍

Entryinfo

Created: 05/26/2016 09:41
Updated: 08/22/2022 09:59
Changes: 05/26/2016 09:41 (64), 12/14/2018 10:07 (14), 08/22/2022 09:57 (5), 08/22/2022 09:59 (1)
Complete: 🔍
Cache ID: 216::103

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