Advisory Details

November 21st, 2018

Microsoft Windows NtGdiExtTextOutW Out-Of-Bounds Write Privilege Escalation Vulnerability

ZDI-18-1357
ZDI-CAN-6991

CVE ID CVE-2018-8553
CVSS SCORE 8.4, AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AFFECTED VENDORS Microsoft
AFFECTED PRODUCTS Windows
VULNERABILITY DETAILS

This vulnerability allows local attackers to escalate privileges on vulnerable installations of Microsoft Windows. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.

The specific flaw exists within the kernel-mode routines that output text to a device context. The issue results from the lack of proper validation of user-supplied data, which can result in a memory access past the end of an allocated buffer. An attacker can leverage this vulnerability to escalate privilege to the level of SYSTEM.

ADDITIONAL DETAILS Microsoft has issued an update to correct this vulnerability. More details can be found at:
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8553
DISCLOSURE TIMELINE
  • 2018-09-19 - Vulnerability reported to vendor
  • 2018-11-21 - Coordinated public release of advisory
  • 2023-06-22 - Advisory Updated
CREDIT GDPR
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