Advisory Details

April 11th, 2017

Microsoft Windows Font Object Buffer Overflow Privilege Escalation Vulnerability

ZDI-17-285
ZDI-CAN-4337

CVE ID CVE-2017-0155
CVSS SCORE 7.2, AV:L/AC:L/Au:N/C:C/I:C/A:C
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 processing of font data in win32k.sys. By making API calls with crafted parameters, code can trigger an overflow of a buffer. An attacker can leverage this vulnerability to escalate privilege to 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-2017-0155
DISCLOSURE TIMELINE
  • 2016-12-12 - Vulnerability reported to vendor
  • 2017-04-11 - Coordinated public release of advisory
CREDIT bear13oy of CloverSec Labs
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