Windows lockscreen bypass in Cortana

Published: 2018-08-14

Risk	Low
Patch available	YES
Number of vulnerabilities	1
CVE-ID	CVE-2018-8253
CWE-ID	CWE-264
Exploitation vector	Local
Public exploit	N/A
Vulnerable software Subscribe	Windows Operating systems & Components / Operating system Windows Server Operating systems & Components / Operating system
Vendor	Microsoft

Security Bulletin

This security bulletin contains one low risk vulnerability.

1) Security restrictions bypass

EUVDB-ID: #VU14407

Risk: Low

CVSSv3.1: 4 [CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-8253

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

Exploit availability: No

Description

The vulnerability allows a local attacker to bypass lockscreen.

The vulnerability exists within Microsoft Cortana code that allows arbitrary website browsing on the lockscreen. A user with physical access to device can access vimctim's browser and steal browser stored passwords or log on to websites as another user.

Successful exploitation of the vulnerability requires access to the console and the system must have Microsoft Cortana assistance enabled.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Windows: 10

Windows Server: 2016

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8253

Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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