Privilege escalation in xen (Alpine package)

1) Privilege escalation

EUVDB-ID: #VU7953

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 - Permissions, Privileges, and Access Controls

Exploit availability: No

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 (Alpine package): 4.5.0-r0 - 4.6.3-r12

External links

http://git.alpinelinux.org/aports/commit/?id=4e31617722f0cbfc0e07928c7cc27aca51e667d8
http://git.alpinelinux.org/aports/commit/?id=d19612e9b3adfc33b29c071630e17fd1a15f36cd
http://git.alpinelinux.org/aports/commit/?id=48b94ffb4d6e3dda3dabb22b8c08089814fb86dc
http://git.alpinelinux.org/aports/commit/?id=605bcdc44def7408f05991fd6ecf6f7dfe7e683c

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.