SB2020101359 - Multiple vulnerabilities in Microsoft Windows

Description

This security bulletin contains information about 3 vulnerabilities.

1) Spoofing attack (CVE-ID: CVE-2020-16922)

CWE-ID: CWE-451 - User Interface (UI) Misrepresentation of Critical Information (Clickjacking, spoofing)

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

The vulnerability allows a local attacker to perform spoofing attack.

The vulnerability exists due to Windows incorrectly validates file signatures. A local attacker can spoof page content, bypass security features and load improperly signed files.

2) Security Features (CVE-ID: CVE-2020-16910)

CWE-ID: CWE-254 - Security Features

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

This vulnerability allows a local  attacker to bypass security rescritions feature.

The vulnerability exists due to the Microsoft Windows fails to handle file creation permissions. A local attacker can run a specially crafted application to bypass Unified Extensible Firmware Interface (UEFI) variable security in Windows.

3) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2020-16877)

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

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

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to the way Windows handles reparse points. A local user can create a malicious application, launch it on the system and overwrite or delete a targeted file that would normally require elevated permissions.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-16922
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-16910
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-16877