Description
A remote code execution vulnerability exists when the Windows Print Spooler service improperly performs privileged file operations. An attacker who successfully exploited this vulnerability could run arbitrary code with SYSTEM privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.
UPDATE July 7, 2021: The security update for Windows Server 2012, Windows Server 2016 and Windows 10, Version 1607 have been released. Please see the Security Updates table for the applicable update for your system. We recommend that you install these updates immediately. If you are unable to install these updates, see the FAQ and Workaround sections in this CVE for information on how to help protect your system from this vulnerability.
In addition to installing the updates, in order to secure your system, you must confirm that the following registry settings are set to 0 (zero) or are not defined (Note: These registry keys do not exist by default, and therefore are already at the secure setting.), also that your Group Policy setting are correct (see FAQ):
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Printers\PointAndPrint
NoWarningNoElevationOnInstall = 0 (DWORD) or not defined (default setting)
UpdatePromptSettings = 0 (DWORD) or not defined (default setting)
Having NoWarningNoElevationOnInstall set to 1 makes your system vulnerable by design.
UPDATE July 6, 2021: Microsoft has completed the investigation and has released security updates to address this vulnerability. Please see the Security Updates table for the applicable update for your system. We recommend that you install these updates immediately. If you are unable to install these updates, see the FAQ and Workaround sections in this CVE for information on how to help protect your system from this vulnerability. See also KB5005010: Restricting installation of new printer drivers after applying the July 6, 2021 updates.
Note that the security updates released on and after July 6, 2021 contain protections for CVE-2021-1675 and the additional remote code execution exploit in the Windows Print Spooler service known as “PrintNightmare”, documented in CVE-2021-34527.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Microsoft | Windows 10 Version 1507 | 10.0.10240.0 – < 10.0.10240.18969 | 10.0.10240.18969 |
| Microsoft | Windows 10 Version 1607 | 10.0.14393.0 – < 10.0.14393.4470 | 10.0.14393.4470 |
| Microsoft | Windows 10 Version 1809 | 10.0.17763.0 – < 10.0.17763.2029, 10.0.0 – < 10.0.17763.2029 | 10.0.17763.2029 |
| Microsoft | Windows 10 Version 20H2 | 10.0.0 – < 10.0.19042.1083 | 10.0.19042.1083 |
| Microsoft | Windows 10 Version 21H2 | 10.0.19044.0 – < 10.0.19044.1415 | 10.0.19044.1415 |
| Microsoft | Windows 10 Version 22H2 | 10.0.19045.0 – < 10.0.19045.2251 | 10.0.19045.2251 |
| Microsoft | Windows 11 version 21H2 | 10.0.22000.0 – < 10.0.22000.318 | 10.0.22000.318 |
| Microsoft | Windows 11 version 22H2 | 10.0.22621.0 – < 10.0.22621.674 | 10.0.22621.674 |
| Microsoft | Windows 8.1 | 6.3.0 – < 6.3.9600.20046 | 6.3.9600.20046 |
| Microsoft | Windows Server 2008 R2 Service Pack 1 | 6.1.7601.0 – < 6.1.7601.25633 | 6.1.7601.25633 |
| Microsoft | Windows Server 2008 R2 Service Pack 1 (Server Core installation) | 6.1.7601.0 – < 6.1.7601.25633 | 6.1.7601.25633 |
| Microsoft | Windows Server 2008 Service Pack 2 | 6.0.6003.0 – < 6.0.6003.21138 | 6.0.6003.21138 |
| Microsoft | Windows Server 2008 Service Pack 2 (Server Core installation) | 6.0.6003.0 – < 6.0.6003.21138 | 6.0.6003.21138 |
| Microsoft | Windows Server 2012 | 6.2.9200.0 – < 6.2.9200.23383 | 6.2.9200.23383 |
| Microsoft | Windows Server 2012 (Server Core installation) | 6.2.9200.0 – < 6.2.9200.23383 | 6.2.9200.23383 |
| Microsoft | Windows Server 2012 R2 | 6.3.9600.0 – < 6.3.9600.20046 | 6.3.9600.20046 |
| Microsoft | Windows Server 2012 R2 (Server Core installation) | 6.3.9600.0 – < 6.3.9600.20046 | 6.3.9600.20046 |
| Microsoft | Windows Server 2016 | 10.0.14393.0 – < 10.0.14393.4470 | 10.0.14393.4470 |
| Microsoft | Windows Server 2016 (Server Core installation) | 10.0.14393.0 – < 10.0.14393.4470 | 10.0.14393.4470 |
| Microsoft | Windows Server 2019 | 10.0.17763.0 – < 10.0.17763.2029 | 10.0.17763.2029 |
| Microsoft | Windows Server 2019 (Server Core installation) | 10.0.17763.0 – < 10.0.17763.2029 | 10.0.17763.2029 |
| Microsoft | Windows Server 2022 | 10.0.20348.0 – < 10.0.20348.230 | 10.0.20348.230 |
| Microsoft | Windows Server version 20H2 | 10.0.0 – < 10.0.19042.1083 | 10.0.19042.1083 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Metasploit 1 module
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Print Spooler Remote DLL Injection
exploit/windows/dcerpc/cve_2021_1675_printnightmare
GitHub 30 repositories · most starred shown
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byt3bl33d3r/ItWasAllADream ★ 803 · Jul 5, 2021
A PrintNightmare (CVE-2021-34527) Python Scanner. Scan entire subnets for hosts vulnerable to the PrintNightmare RCE
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JohnHammond/CVE-2021-34527 ★ 330 · Jul 2, 2021
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nemo-wq/PrintNightmare-CVE-2021-34527 ★ 181 · Jul 3, 2021
PrintNightmare - Windows Print Spooler RCE/LPE Vulnerability (CVE-2021-34527, CVE-2021-1675) proof of concept exploits
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m8sec/CVE-2021-34527 ★ 119 · Aug 23, 2022
PrintNightmare (CVE-2021-34527) PoC Exploit
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hackerhouse-opensource/cve-2021-34527 ★ 23 · Sep 5, 2022
CVE-2021-34527 AddPrinterDriverEx() Privilege Escalation
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Tomparte/PrintNightmare ★ 3 · Jul 28, 2021
To fight against Windows security breach PrintNightmare! (CVE-2021-34527, CVE-2021-1675)
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dywhoami/CVE-2021-34527-Scanner-Based-On-cube0x0-POC ★ 3 · Jul 9, 2021
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powershellpr0mpt/PrintNightmare-CVE-2021-34527 ★ 3 · Jul 7, 2021
How to fix the PrintNightmare vulnerability
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0xirison/PrintNightmare-Patcher ★ 2 · Jul 12, 2021
A patch for PrintNightmare vulnerability that occurs to print spooler service for Windows machines [CVE-2021-34527]
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rdboboia/disable-RegisterSpoolerRemoteRpcEndPoint ★ 2 · Jul 5, 2021
Workaround for Windows Print Spooler Remote Code Execution Vulnerability(CVE-2021-34527). See: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34527
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 2
- MSRC-CVE-2021-34527 Windows Print Spooler Remote Code Execution Vulnerability Microsoft Security Response Center · Jun 13, 2023
- VDE-2021-034 Pepperl+Fuchs: Security Advisory for PrintNightmare Vulnerability in multiple HMI Devices CERT@VDE · Jul 30, 2021
References
- Windows Print Spooler Remote Code Execution Vulnerability vendor-advisory patch