SB2022011126 - Multiple vulnerabilities in Microsoft Win32k

Description

This security bulletin contains information about 3 vulnerabilities.

1) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2022-21887)

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

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/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 application does not properly impose security restrictions in Win32k, which leads to security restrictions bypass and privilege escalation.

2) Information disclosure (CVE-ID: CVE-2022-21876)

CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor

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

The vulnerability allows a local user to gain access to potentially sensitive information.

The vulnerability exists due to excessive data output by the application in Win32k. A local user can gain unauthorized access to sensitive information on the system.

3) Buffer overflow (CVE-ID: CVE-2022-21882)

CWE-ID: CWE-119 - Memory corruption

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

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

The vulnerability exists due to a boundary error within the Win32k.sys driver. A local user can run a specially crafted program to trigger a buffer overflow and execute arbitrary code on the system with elevated privileges.

Note, the vulnerability is being actively exploited in the wild.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2022-21887
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2022-21876
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2022-21882