Xen up to 4.8.x shadow-paging race condition

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.4$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in Xen up to 4.8.x. This vulnerability affects unknown code of the component shadow-paging. Such manipulation leads to race condition. This vulnerability is referenced as CVE-2017-10915. It is possible to launch the attack remotely. No exploit is available. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability was found in Xen up to 4.8.x (Virtualization Software). It has been rated as critical. Affected by this issue is an unknown function of the component shadow-paging. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Impacted is confidentiality, integrity, and availability. CVE summarizes:

The shadow-paging feature in Xen through 4.8.x mismanages page references and consequently introduces a race condition, which allows guest OS users to obtain Xen privileges, aka XSA-219.

The bug was discovered 06/20/2017. The weakness was published 07/05/2017 by Andrew Cooper with Citrix as XSA-219 as confirmed security advisory (Website). The advisory is shared for download at xenbits.xen.org. This vulnerability is handled as CVE-2017-10915 since 07/04/2017. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly 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 99174†). Similar entries are available at VDB-103037, VDB-103038, VDB-103039 and VDB-103041. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.7
VulDB Meta Temp Score: 7.6

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

NVD Base Score: 9.0
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

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 🔍
10/22/2019 +827 days 🔍

Sourcesinfo

Advisory: XSA-219
Researcher: Andrew Cooper
Organization: Citrix
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-10915 (🔍)
GCVE (CVE): GCVE-0-2017-10915
GCVE (VulDB): GCVE-100-103040

OVAL: 🔍

SecurityFocus: 99174 - Xen 'shadow/common.c' Privilege Escalation Vulnerability

See also: 🔍

Entryinfo

Created: 07/05/2017 10:30
Updated: 10/22/2019 09:58
Changes: 07/05/2017 10:30 (77), 10/22/2019 09:58 (6)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Want to know what is going to be exploited?

We predict KEV entries!