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.
3.5	$0-$5k	0.00

A vulnerability has been found in XenSource Xen 3.4/4.0/4.1/4.2/4.3 (Virtualization Software) and classified as problematic. Affected by this vulnerability is an unknown part of the component I/O Decoder. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-264. As an impact it is known to affect availability.

The weakness was disclosed 03/31/2015 by Jan Beulich with SuSE as XSA-126 as confirmed security advisory (Website). The advisory is shared at xenbits.xen.org. This vulnerability is known as CVE-2015-2756 since 03/27/2015. The exploitation appears to be easy. An attack has to be approached locally. 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 83422 (Debian DSA-3259-1 : qemu - security update (Venom)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks. The commercial vulnerability scanner Qualys is able to test this issue with plugin 370035 (Citrix XenServer Security Update (CTX201145)).

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 databases at X-Force (101906) and Tenable (83422). The entries 74129, 74496, 75034 and 75680 are pretty similar.

Productinfo

Type

• Virtualization Software

Vendor

• XenSource

Name

• Xen

Version

• 3.4
• 4.0
• 4.1
• 4.2
• 4.3

License

• open-source

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv3info

VulDB Meta Base Score: 4.0
VulDB Meta Temp Score: 3.5

VulDB Base Score: 4.0
VulDB Temp Score: 3.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

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-264
ATT&CK: T1068

Local: Yes
Remote: No

Availability: 🔍
Status: Unproven

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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

Nessus ID: 83422
Nessus Name: Debian DSA-3259-1 : qemu - security update (Venom)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍

OpenVAS ID: 703259
OpenVAS Name: Debian Security Advisory DSA 3259-1 (qemu - security update)
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

03/27/2015 🔍
03/31/2015 +4 days 🔍
03/31/2015 +0 days 🔍
03/31/2015 +0 days 🔍
04/01/2015 +1 days 🔍
04/01/2015 +0 days 🔍
04/01/2015 +0 days 🔍
04/01/2015 +0 days 🔍
04/02/2015 +1 days 🔍
05/02/2022 +2587 days 🔍

Sourcesinfo

Vendor: citrix.com

Advisory: XSA-126
Researcher: Jan Beulich
Organization: SuSE
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2015-2756 (🔍)
OVAL: 🔍

X-Force: 101906 - Xen I/O decode denial of service
SecurityTracker: 1031998 - Xen QEMU PCI Comman Register Access Lets Local Guest Users Deny Service on the Host System
Vulnerability Center: 49310 - Xen 3.3.x through 4.5.x Local DoS via Unsupported Request Response, Medium
SecurityFocus: 72577 - Xen CVE-2015-2756 Denial of Service Vulnerability

See also: 🔍

Entryinfo

Created: 04/01/2015 10:50 AM
Updated: 05/02/2022 07:23 AM
Changes: 04/01/2015 10:50 AM (74), 06/24/2017 09:32 AM (9), 05/02/2022 07:17 AM (3), 05/02/2022 07:23 AM (1)
Complete: 🔍

Discussion

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