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.
4.5	$0-$5k	0.00

A vulnerability was found in XenSource Xen (Virtualization Software) (the affected version is unknown). It has been declared as problematic. Affected by this vulnerability is an unknown code of the component libxl. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect availability. The summary by CVE is:

The libxl device-handling in Xen through 4.6.x allows local guest OS users with access to the driver domain to cause a denial of service (management tool confusion) by manipulating information in the backend directories in xenstore.

The weakness was released 06/02/2016 as XSA-178 as confirmed security advisory (Website). The advisory is shared at xenbits.xen.org. This vulnerability is known as CVE-2016-4963 since 05/24/2016. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1068 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 91937 (FreeBSD : xen-tools -- Unsanitised driver domain input in libxl device handling (e589ae90-4212-11e6-942d-bc5ff45d0f28)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family FreeBSD Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 169079 (SUSE Enterprise Linux Security Update for xen (SUSE-SU-2016:2100-1)).

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 (91937). Entry connected to this vulnerability is available at 82557.

Productinfo

Type

• Virtualization Software

Vendor

• XenSource

Name

• Xen

License

• open-source

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

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

CVSSv3info

VulDB Meta Base Score: 4.7
VulDB Meta Temp Score: 4.6

VulDB Base Score: 4.7
VulDB Temp Score: 4.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.7
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
unlock	unlock	unlock	unlock	unlock	unlock
unlock	unlock	unlock	unlock	unlock	unlock
unlock	unlock	unlock	unlock	unlock	unlock

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

NVD Base Score: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-284 / CWE-266
ATT&CK: T1068

Local: No
Remote: Yes

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: 91937
Nessus Name: FreeBSD : xen-tools -- Unsanitised driver domain input in libxl device handling (e589ae90-4212-11e6-942d-bc5ff45d0f28)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 11027
OpenVAS Name: Fedora Update for xen FEDORA-2016-389be30b95
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

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

Timelineinfo

05/24/2016 🔍
06/02/2016 +9 days 🔍
06/02/2016 +0 days 🔍
06/02/2016 +0 days 🔍
06/03/2016 +1 days 🔍
06/07/2016 +4 days 🔍
07/05/2016 +28 days 🔍
01/01/2019 +910 days 🔍

Sourcesinfo

Vendor: citrix.com

Advisory: XSA-178
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2016-4963 (🔍)
SecurityTracker: 1036024

See also: 🔍

Entryinfo

Created: 06/03/2016 12:01
Updated: 01/01/2019 12:42
Changes: 06/03/2016 12:01 (68), 01/01/2019 12:42 (10)
Complete: 🔍

Discussion

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