Xen 4.4.x/4.5.x/4.6.x/4.7.x x86 Null Segment Access Control Guest access control
CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
---|---|---|
7.5 | $0-$5k | 0.00 |
A vulnerability was found in Xen 4.4.x/4.5.x/4.6.x/4.7.x (Virtualization Software). It has been classified as critical. Affected is an unknown code of the component x86 Null Segment Access Control. The manipulation with an unknown input leads to a access control vulnerability (Guest). CWE is classifying the issue as CWE-264. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:
The x86 emulator in Xen does not properly treat x86 NULL segments as unusable when accessing memory, which might allow local HVM guest users to gain privileges via vectors involving "unexpected" base/limit values.
The bug was discovered 11/22/2016. The weakness was shared 11/22/2016 by Andrew Cooper with Citrix as XSA-191 as confirmed security advisory (Website). The advisory is shared for download at xenbits.xen.org. The vendor cooperated in the coordination of the public release. This vulnerability is traded as CVE-2016-9386 since 11/17/2016. The exploitability is told to be easy. The attack needs to be approached locally. A authentication is needed for exploitation. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1068.
The vulnerability scanner Nessus provides a plugin with the ID 900047 , which helps to determine the existence of the flaw in a target environment. The commercial vulnerability scanner Qualys is able to test this issue with plugin 169439 (SUSE Enterprise Linux Security Update for xen (SUSE-SU-2016:3174-1)).
Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.
The vulnerability is also documented in the vulnerability database at Tenable (900047). The entries 92454, 92455, 92462 and 93307 are related to this item.
Product
Type
Name
Version
License
CPE 2.3
CPE 2.2
CVSSv4
VulDB CVSS-B Score: 🔍VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 7.8VulDB 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: 🔍
CVSSv2
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Vector | Complexity | Authentication | Confidentiality | Integrity | Availability |
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VulDB Base Score: 🔍
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Exploiting
Name: GuestClass: Access control / Guest
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 |
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Today | unlock | unlock | unlock | unlock |
Nessus ID: 900047
Nessus File: 🔍
OpenVAS ID: 703729
OpenVAS Name: Debian Security Advisory DSA 3729-1 (xen - security update)
OpenVAS File: 🔍
OpenVAS Family: 🔍
Qualys ID: 🔍
Qualys Name: 🔍
Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: PatchStatus: 🔍
Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍
Timeline
11/17/2016 🔍11/22/2016 🔍
11/22/2016 🔍
11/22/2016 🔍
11/22/2016 🔍
11/24/2016 🔍
11/25/2016 🔍
01/23/2017 🔍
06/10/2019 🔍
Sources
Advisory: XSA-191Researcher: Andrew Cooper
Organization: Citrix
Status: Confirmed
Confirmation: 🔍
Coordinated: 🔍
CVE: CVE-2016-9386 (🔍)
OVAL: 🔍
SecurityTracker: 1037340
SecurityFocus: 94471 - Xen CVE-2016-9386 Privilege Escalation Vulnerability
See also: 🔍
Entry
Created: 11/25/2016 11:52Updated: 06/10/2019 06:21
Changes: 11/25/2016 11:52 (70), 06/10/2019 06:21 (13)
Complete: 🔍
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