Permissions, Privileges, and Access Controls in Fedoraproject Fedora

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU40677

Risk: High

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2015-5166

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

Use-after-free vulnerability in QEMU in Xen 4.5.x and earlier does not completely unplug emulated block devices, which allows local HVM guest users to gain privileges by unplugging a block device twice.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Fedora: 21 - 22

Xen: 4.5.1 - 22

CPE2.3

• cpe:2.3:o:fedoraproject:fedora:21:*:*:*:*:*:*:*
• cpe:2.3:o:fedoraproject:fedora:22:*:*:*:*:*:*:*
• cpe:2.3:a:xen_project:xen:4.5.1:*:*:*:*:*:*:*
• cpe:2.3:a:xen_project:xen:21:*:*:*:*:*:*:*
• cpe:2.3:a:xen_project:xen:22:*:*:*:*:*:*:*

External links

https://lists.fedoraproject.org/pipermail/package-announce/2015-September/165373.html
https://lists.fedoraproject.org/pipermail/package-announce/2015-September/167792.html
https://lists.fedoraproject.org/pipermail/package-announce/2015-September/167820.html
https://www.securityfocus.com/bid/76152
https://www.securitytracker.com/id/1033175
https://xenbits.xen.org/xsa/advisory-139.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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