AEGLIX vulnerability intelligence
CVE-2021-34527
HIGH · CVSS 8.8 · Analyzed
Published: 2021-07-02 · Updated: 2026-08-10 · Source: NVD
Vulnerability overview
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.
Severity and scoring
- CVSS score
- 8.8 · HIGH
- CVSS version
- 3.1
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weaknesses
- NVD-CWE-noinfo
CVSS measures technical severity; it does not establish whether this vulnerability is being exploited in your environment.
Known exploitation and remediation
Listed in CISA’s Known Exploited Vulnerabilities catalog.
- Affected product
- Microsoft · Windows
- Added to catalog
- 2021-11-03
- Required action
- Apply updates per vendor instructions.
- CISA remediation due date
- 2022-05-03
CISA deadlines apply to the organizations covered by its directives. Confirm your own remediation requirements.
Verify affected versions and patch availability in the vendor advisory before making changes.
Affected products and versions
cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:*:*
Before (exclusive): 10.0.10240.18969
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:*:*
Before (exclusive): 10.0.14393.4470
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:*:*
Before (exclusive): 10.0.17763.2029
cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:*:*
Before (exclusive): 10.0.19042.1083
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:*
Before (exclusive): 10.0.19044.1415
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:*
Before (exclusive): 10.0.19045.2251
cpe:2.3:o:microsoft:windows_11_21h2:*:*:*:*:*:*:*:*
Before (exclusive): 10.0.22000.318
cpe:2.3:o:microsoft:windows_11_22h2:*:*:*:*:*:*:*:*
Before (exclusive): 10.0.22621.674
cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
Before (exclusive): 10.0.14393.4470
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
Before (exclusive): 10.0.17763.2029
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
Before (exclusive): 10.0.20348.230
cpe:2.3:o:microsoft:windows_server_20h2:*:*:*:*:*:*:*:*
Before (exclusive): 10.0.19042.1083
These are NVD CPE applicability entries. Some products depend on configuration conditions; consult the official record to confirm applicability.
Advisories and references
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34527
Patch · Vendor Advisory
- http://packetstormsecurity.com/files/167261/Print-Spooler-Remote-DLL-Injection.html
Exploit · Third Party Advisory · VDB Entry
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34527
Mitigation · Patch · Vendor Advisory
- https://www.kb.cert.org/vuls/id/383432
Third Party Advisory · US Government Resource
- https://www.vicarius.io/vsociety/posts/cve-2021-34527-printnightmare-detection-script
Exploit · Third Party Advisory
- https://www.vicarius.io/vsociety/posts/cve-2021-34527-printnightmare-mitigation-script
Exploit · Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34527
US Government Resource