XenSource Xen 3.4/4.0/4.1/4.2/4.3 I/O Decoder access control

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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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.







CPE 2.3info

CPE 2.2info


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: 🔍



VulDB Base Score: 🔍
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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: 🔍


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: 🔍
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Qualys ID: 🔍
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Threat Intelligenceinfo

Interest: 🔍
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Recommended: Patch
Status: 🔍

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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 🔍


Vendor: citrix.com

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

CVE: CVE-2015-2756 (🔍)

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: 🔍


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: 🔍


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