SB2019091022 - Privilege escalation in Microsoft Windows Win32k.sys driver

Description

This security bulletin contains information about 2 vulnerabilities.

1) Buffer overflow (CVE-ID: CVE-2019-1285)

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:U/U:Clear

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

The vulnerability exists due to a boundary error when processing objects in memory within the Win32k component. A local user can create a malicious application, launch it on the system and execute arbitrary code with SYSTEM privileges.

2) NULL pointer dereference (CVE-ID: CVE-2019-1256)

CWE-ID: CWE-476 - NULL Pointer Dereference

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:P/U:Clear

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

The vulnerability exists due to a NULL pointer dereference when processing objects in memory within the Win32k component. A local user can create a malicious application, launch it on the system and execute arbitrary code with SYSTEM privileges.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1285
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1256
• https://cpr-zero.checkpoint.com/vulns/cprid-2137/