SB2018081434 - Security restrictions bypass in Microsoft Windows Device Guard

Description

This security bulletin contains information about 2 vulnerabilities.

1) Code injection (CVE-ID: CVE-2018-8204)

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local attacker to bypass security restrictions on the target system.

The vulnerability exists due to an error when PowerShell exposes functions and processes user supplied code. A local attacker can inject code into a trusted PowerShell process to bypass the Device Guard Code Integrity policy on the local machine.

2) Code injection (CVE-ID: CVE-2018-8200)

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local attacker to bypass security restrictions on the target system.

The vulnerability exists due to an error when PowerShell exposes functions and processes user supplied code. A local attacker can inject code into a trusted PowerShell process to bypass the Device Guard Code Integrity policy on the local machine.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8204
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8200