Xen up to 4.8.x Event Channel Port null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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7.4$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Xen up to 4.8.x. Impacted is an unknown function of the component Event Channel Port Handler. Executing a manipulation can lead to null pointer dereference. This vulnerability is tracked as CVE-2017-10917. The attack can be launched remotely. No exploit exists. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability classified as critical was found in Xen up to 4.8.x (Virtualization Software). This vulnerability affects some unknown functionality of the component Event Channel Port Handler. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect confidentiality, and availability. CVE summarizes:

Xen through 4.8.x does not validate the port numbers of polled event channel ports, which allows guest OS users to cause a denial of service (NULL pointer dereference and host OS crash) or possibly obtain sensitive information, aka XSA-221.

The bug was discovered 06/20/2017. The weakness was disclosed 07/05/2017 with Oracle as XSA-221 as confirmed security advisory (Website). The advisory is available at xenbits.xen.org. This vulnerability was named CVE-2017-10917 since 07/04/2017. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. The technical details are unknown and an exploit is not available.

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 99157†). The entries VDB-103037, VDB-103038, VDB-103039 and VDB-103040 are pretty similar. If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.8
VulDB Meta Temp Score: 7.6

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.1
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
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Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
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: 103302
OpenVAS Name: Citrix XenServer Multiple Security Updates
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-221
Researcher: Ankur Arora
Organization: Oracle
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-10917 (🔍)
GCVE (CVE): GCVE-0-2017-10917
GCVE (VulDB): GCVE-100-103042

OVAL: 🔍

SecurityFocus: 99157 - Xen 'xen/arch/x86/irq.c' NULL pointer Dereference Remote Denial of Service Vulnerability
SecurityTracker: 1038731

See also: 🔍

Entryinfo

Created: 07/05/2017 10:30
Updated: 12/30/2020 17:11
Changes: 07/05/2017 10:30 (78), 10/22/2019 10:06 (5), 12/30/2020 17:05 (3), 12/30/2020 17:11 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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