Xen up to 4.9.x Shadow Mode memory corruption

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CTI Interest Score
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A vulnerability, which was classified as critical, has been found in Xen up to 4.9.x (Virtualization Software). Affected by this issue is an unknown function of the component Shadow Mode. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

An issue was discovered in Xen through 4.9.x allowing guest OS users to cause a denial of service (host OS crash) or gain host OS privileges by leveraging an incorrect mask for reference-count overflow checking in shadow mode.

The bug was discovered 12/12/2017. The weakness was presented 12/12/2017 by Jan Beulich (oss-sec). The advisory is available at openwall.com. This vulnerability is handled as CVE-2017-17563 since 12/12/2017. Local access is required to approach this attack. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available.

The vulnerability scanner Nessus provides a plugin with the ID 105491 (Xen Function Page Use Shadow Mode Reference Counting Improper Overflow Check Guest-to-Host DoS (XSA-249)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Misc. and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 170761 (SUSE Enterprise Linux Security Update for xen (SUSE-SU-2018:0438-1)).

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 databases at Tenable (105491) and SecurityFocus (BID 102169†).






CPE 2.3info

CPE 2.2info


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VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
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NVD Base Score: 7.8
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Class: Memory corruption
CWE: CWE-119

Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

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Nessus ID: 105491
Nessus Name: Xen Function Page Use Shadow Mode Reference Counting Improper Overflow Check Guest-to-Host DoS (XSA-249)
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OpenVAS ID: 63884
OpenVAS Name: Fedora Update for xen FEDORA-2017-5945560816
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Threat Intelligenceinfo

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Recommended: Patch
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12/12/2017 🔍
12/12/2017 +0 days 🔍
12/12/2017 +0 days 🔍
12/12/2017 +0 days 🔍
12/12/2017 +0 days 🔍
12/12/2017 +0 days 🔍
12/13/2017 +1 days 🔍
12/29/2017 +16 days 🔍
01/17/2023 +1845 days 🔍


Advisory: DLA 1230-1
Researcher: Jan Beulich
Status: Not defined
Confirmation: 🔍

CVE: CVE-2017-17563 (🔍)

SecurityFocus: 102169 - Xen 'Hypervisor' Memory Corruption Vulnerability
SecurityTracker: 1040769


Created: 12/13/2017 08:11 AM
Updated: 01/17/2023 02:10 PM
Changes: 12/13/2017 08:11 AM (73), 12/14/2019 09:40 AM (7), 01/27/2021 09:15 AM (3), 01/17/2023 02:10 PM (3)
Complete: 🔍
Cache ID: 44:6D6:40


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