Xen up to 4.9 Grant Entry information disclosure

CVSS Meta Temp Score
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CTI Interest Score
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4.9$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Xen 4.5/4.6/4.7/4.8/4.9. The affected element is an unknown function of the component Grant Entry Handler. Performing a manipulation results in information disclosure. This vulnerability is cataloged as CVE-2017-12855. The attack must be initiated from a local position. There is no exploit available. Applying a patch is the recommended action to fix this issue.

Detailsinfo

A vulnerability classified as problematic has been found in Xen 4.5/4.6/4.7/4.8/4.9 (Virtualization Software). This affects an unknown functionality of the component Grant Entry Handler. 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. The summary by CVE is:

Xen maintains the _GTF_{read,writ}ing bits as appropriate, to inform the guest that a grant is in use. A guest is expected not to modify the grant details while it is in use, whereas the guest is free to modify/reuse the grant entry when it is not in use. Under some circumstances, Xen will clear the status bits too early, incorrectly informing the guest that the grant is no longer in use. A guest may prematurely believe that a granted frame is safely private again, and reuse it in a way which contains sensitive information, while the domain on the far end of the grant is still using the grant. Xen 4.9, 4.8, 4.7, 4.6, and 4.5 are affected.

The bug was discovered 08/15/2017. The weakness was shared 08/15/2017 by Jan Beulich as XSA-230 as confirmed security advisory (Website). The advisory is shared at xenbits.xen.org. This vulnerability is uniquely identified as CVE-2017-12855 since 08/15/2017. An attack has to be approached locally. 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 scanner Nessus provides a plugin with the ID 102526 (Citrix XenServer Multiple Vulnerabilities (CTX225941)), 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 176145 (Debian Security Update for xen (DSA 3969-1)).

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 (102526) and SecurityFocus (BID 100341†). The entries VDB-105388, VDB-105389 and VDB-105391 are related to this item. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.1
VulDB Meta Temp Score: 5.1

VulDB Base Score: 3.8
VulDB Temp Score: 3.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.5
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: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 102526
Nessus Name: Citrix XenServer Multiple Vulnerabilities (CTX225941)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 53376
OpenVAS Name: Debian Security Advisory DSA 3969-1 (xen - 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

08/15/2017 🔍
08/15/2017 +0 days 🔍
08/15/2017 +0 days 🔍
08/15/2017 +0 days 🔍
08/15/2017 +0 days 🔍
08/15/2017 +0 days 🔍
08/16/2017 +1 days 🔍
08/16/2017 +0 days 🔍
01/09/2021 +1242 days 🔍

Sourcesinfo

Advisory: XSA-230
Researcher: Jan Beulich
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-12855 (🔍)
GCVE (CVE): GCVE-0-2017-12855
GCVE (VulDB): GCVE-100-105309

OVAL: 🔍

SecurityFocus: 100341 - Xen CVE-2017-12855 Local Information Disclosure Vulnerability
SecurityTracker: 1039177

See also: 🔍

Entryinfo

Created: 08/16/2017 03:48
Updated: 01/09/2021 13:18
Changes: 08/16/2017 03:48 (76), 11/07/2019 15:40 (5), 01/09/2021 13:18 (2)
Complete: 🔍
Cache ID: 216::103

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