CVE-2020-1259: Windows Host Guardian Service Security Feature Bypass Vulnerability

Overview

Severity
Medium (CVSS 4.3)
CVSS Vector
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:P/RL:O/RC:C
Category
Security Feature Bypass
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2020-Jun
Released
2020-06-09
EPSS Score
5.08% (percentile: 89.8%)

Description

A security feature bypass vulnerability exists when Windows Host Guardian Service improperly handles hashes recorded and logged. An attacker who successfully exploited the vulnerability could tamper with the log file. In an attack scenario, an attacker can change existing event log types to a type the parsers do not interpret allowing an attacker to append their own hash without triggering an alert. The update addresses the vulnerability by correcting how Windows Host Guardian Service handles logging of the measured boot hash.

Affected Products (30)

Windows

  • Windows Server, version 2004 (Server Core installation)
  • Windows 10 Version 1803 for 32-bit Systems
  • Windows 10 Version 1803 for x64-based Systems
  • Windows Server, version 1803 (Server Core Installation)
  • Windows 10 Version 1803 for ARM64-based Systems
  • Windows 10 Version 1809 for 32-bit Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows 10 Version 1809 for ARM64-based Systems
  • Windows Server 2019
  • Windows Server 2019 (Server Core installation)
  • Windows 10 Version 1709 for 32-bit Systems
  • Windows 10 Version 1709 for x64-based Systems
  • Windows 10 Version 1709 for ARM64-based Systems
  • Windows 10 Version 1903 for 32-bit Systems
  • Windows 10 Version 1903 for x64-based Systems
  • Windows 10 Version 1903 for ARM64-based Systems
  • Windows Server, version 1903 (Server Core installation)
  • Windows 10 for 32-bit Systems
  • Windows 10 for x64-based Systems
  • Windows 10 Version 1607 for 32-bit Systems
  • Windows 10 Version 1607 for x64-based Systems
  • Windows Server 2016
  • Windows Server 2016 (Server Core installation)
  • Windows 10 Version 1909 for 32-bit Systems
  • Windows 10 Version 1909 for x64-based Systems
  • Windows 10 Version 1909 for ARM64-based Systems
  • Windows Server, version 1909 (Server Core installation)
  • Windows 10 Version 2004 for ARM64-based Systems
  • Windows 10 Version 2004 for 32-bit Systems
  • Windows 10 Version 2004 for x64-based Systems

Security Updates (7)

Acknowledgments

Eric Chiang of Google

Revision History

  • 2020-06-09: Information published.