Vulnerability identifier: #VU7953

Vulnerability risk: Low

CVSSv3.1: 7 [CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-12855

CWE-ID: CWE-264

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
Xen
Server applications / Virtualization software

Vendor: Xen Project

Description
The vulnerability allows a local attacker on the guest system to gain elevated privileges on the host system.

The weakness exists due to flaws when clearing grant status bits. A local attacker on a guest system may modify or reuse a grant that is still in use by another domain and obtain potentially sensitive information from another guest on the target system.


a flaw when clearing grant status bits prematurely. As a result, a guest system may modify or reuse a grant that is still in use by another domain. A local attacker on a guest system may modify or reuse a grant that is still in use by another domain and obtain potentially sensitive information from another guest on the target system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Xen: 4.5.0 - 4.9.0

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External links
http://xenbits.xen.org/xsa/advisory-230.html

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.