Xen up to 4.8.x vCPU context-switch information disclosure

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Xen up to 4.8.x. This issue affects some unknown processing of the component vCPU context-switch. Performing a manipulation results in information disclosure. This vulnerability is identified as CVE-2017-10916. The attack can be initiated remotely. There is not any exploit available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability classified as problematic has been found in Xen up to 4.8.x (Virtualization Software). This affects an unknown functionality of the component vCPU context-switch. The manipulation with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

The vCPU context-switch implementation in Xen through 4.8.x improperly interacts with the Memory Protection Extensions (MPX) and Protection Key (PKU) features, which makes it easier for guest OS users to defeat ASLR and other protection mechanisms, aka XSA-220.

The bug was discovered 06/20/2017. The weakness was released 07/05/2017 by Andrew Cooper with Citrix as XSA-220 as confirmed security advisory (Website). The advisory is shared at xenbits.xen.org. This vulnerability is uniquely identified as CVE-2017-10916 since 07/04/2017. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1592 for this issue.

The vulnerability was handled as a non-public zero-day exploit for at least 14 days. During that time the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 101638 (Fedora 26 : xen (2017-5c6a9b07a3)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 276751 (Fedora Security Update for xen (FEDORA-2017-c3149b5fcb)).

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 (101638) and SecurityFocus (BID 99167†). Entries connected to this vulnerability are available at VDB-103037, VDB-103038, VDB-103039 and VDB-103040. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

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

VulDB Base Score: 5.6
VulDB Temp Score: 5.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 101638
Nessus Name: Fedora 26 : xen (2017-5c6a9b07a3)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 867773
OpenVAS Name: Fedora Update for xen FEDORA-2017-c3149b5fcb
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

06/20/2017 🔍
06/20/2017 +0 days 🔍
07/04/2017 +14 days 🔍
07/04/2017 +0 days 🔍
07/05/2017 +1 days 🔍
07/05/2017 +0 days 🔍
07/05/2017 +0 days 🔍
07/17/2017 +12 days 🔍
12/30/2020 +1262 days 🔍

Sourcesinfo

Advisory: XSA-220
Researcher: Andrew Cooper
Organization: Citrix
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-10916 (🔍)
GCVE (CVE): GCVE-0-2017-10916
GCVE (VulDB): GCVE-100-103041

OVAL: 🔍

SecurityFocus: 99167 - Xen XSA-220 Information Disclosure Vulnerability
SecurityTracker: 1038730

See also: 🔍

Entryinfo

Created: 07/05/2017 10:30
Updated: 12/30/2020 17:01
Changes: 07/05/2017 10:30 (78), 10/22/2019 10:01 (6), 12/30/2020 17:01 (3)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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