CVE-2020-1337: Windows Print Spooler Elevation of Privilege Vulnerability

Overview

Severity

High (CVSS 7.8)

CVSS Vector

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C

Category

Elevation of Privilege

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2020-Aug

Released

2020-08-11

EPSS Score

55.31% (percentile: 98.1%)

Description

An elevation of privilege vulnerability exists when the Windows Print Spooler service improperly allows arbitrary writing to the file system. An attacker who successfully exploited this vulnerability could run arbitrary code with elevated system privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. To exploit this vulnerability, an attacker would have to log on to an affected system and run a specially crafted script or application. The update addresses the vulnerability by correcting how the Windows Print Spooler Component writes to the file system.

Detection & Weaponization (3 sources)

Maturity: Detection

• Metasploit modules: Microsoft Spooler Local Privilege Elevation Vulnerability
• YARA rules: SIGNATURE_BASE_HKTL_NET_GUID_CVE_2020_1337
• GitHub PoC: 4 repositories

Affected Products (44)

Windows

• Windows 10 Version 2004 for 32-bit Systems
• Windows 10 Version 2004 for ARM64-based Systems
• Windows 10 Version 2004 for x64-based Systems
• Windows Server, version 2004 (Server Core installation)
• Windows 10 Version 1803 for 32-bit Systems
• Windows 10 Version 1803 for x64-based Systems
• 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 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 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 8.1 for 32-bit systems
• Windows 8.1 for x64-based systems
• Windows RT 8.1

ESU

• Windows 7 for 32-bit Systems Service Pack 1
• Windows 7 for x64-based Systems Service Pack 1
• Windows Server 2008 for 32-bit Systems Service Pack 2
• Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
• Windows Server 2008 for x64-based Systems Service Pack 2
• Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
• Windows Server 2008 R2 for x64-based Systems Service Pack 1
• Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
• Windows Server 2012
• Windows Server 2012 (Server Core installation)
• Windows Server 2012 R2
• Windows Server 2012 R2 (Server Core installation)

Security Updates (15)

• 4566782
• 4571709
• 4565349
• 4565351
• 4571741
• 4571692
• 4571694
• 4571729
• 4571719
• 4571703
• 4571723
• 4571730
• 4571746
• 4571736
• 4571702

Acknowledgments

Vte. Javier García Mayén, Junyu Zhou (<a href="https://twitter.com/md5_salt">@md5_salt</a>) of Tencent Security Xuanwu Lab and Wenxu Wu, EoP Master working with <a href="https://vcp.idefense.com">iDefense Labs</a>, Accenture. , Alex Ionescu, <a href="https://www.crowdstrike.com">CrowdStrike Inc.</a>, Zhiniang Peng <a href="https://twitter.com/edwardzpeng">(@edwardzpeng)</a> & Xuefeng Li, Paolo Stagno aka <a href="https://voidsec.com">VoidSec</a>, Anonymous working with <a href="https://www.zerodayinitiative.com/">Trend Micro's Zero Day Initiative</a>, Peleg Hadar (<a href="https://twitter.com/peleghd">@peleghd</a>) and Tomer Bar of SafeBreach Labs.

Revision History

• 2020-08-11: Information published.