Known Exploited Vulnerability
8.8
HIGH
CVE-2021-34527
Microsoft Windows Print Spooler Remote Code Execut - [Actively Exploited]
Description

<p>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.</p> <p>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.</p> <p>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 (<strong>Note</strong>: 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):</p> <ul> <li>HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Printers\PointAndPrint</li> <li>NoWarningNoElevationOnInstall = 0 (DWORD) or not defined (default setting)</li> <li>UpdatePromptSettings = 0 (DWORD) or not defined (default setting)</li> </ul> <p><strong>Having NoWarningNoElevationOnInstall set to 1 makes your system vulnerable by design.</strong></p> <p>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 <a href="https://support.microsoft.com/topic/31b91c02-05bc-4ada-a7ea-183b129578a7">KB5005010: Restricting installation of new printer drivers after applying the July 6, 2021 updates</a>.</p> <p>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.</p>

INFO

Published Date :

July 2, 2021, 10:15 p.m.

Last Modified :

Feb. 2, 2024, 5:24 p.m.

Remotely Exploitable :

Yes !

Impact Score :

5.9

Exploitability Score :

2.8
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

Microsoft Windows Print Spooler contains an unspecified vulnerability due to the Windows Print Spooler service improperly performing privileged file operations. Successful exploitation allows an attacker to perform remote code execution with SYSTEM privileges. The vulnerability is also known under the moniker of PrintNightmare.

Required Action :

Apply updates per vendor instructions.

Notes :

Reference CISA's ED 21-04 (https://www.cisa.gov/emergency-directive-21-04) for further guidance and requirements.

Public PoC/Exploit Available at Github

CVE-2021-34527 has a 202 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

Affected Products

The following products are affected by CVE-2021-34527 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Microsoft windows_7
2 Microsoft windows_8.1
3 Microsoft windows_rt_8.1
4 Microsoft windows_server_2008
5 Microsoft windows_server_2012
6 Microsoft windows_server_2016
7 Microsoft windows_server_2019
8 Microsoft windows_10_1607
9 Microsoft windows_10_1809
10 Microsoft windows_10_20h2
11 Microsoft windows_10_21h2
12 Microsoft windows_10_22h2
13 Microsoft windows_server_2022
14 Microsoft windows_11_21h2
15 Microsoft windows_11_22h2
16 Microsoft windows_10_1507
17 Microsoft windows_server_20h2
18 Microsoft windows_server_2012_r2
19 Microsoft windows_server_2008_r2
20 Microsoft windows_server_2008_sp2
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-34527.

URL Resource
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

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

This cheat sheet contains common enumeration and attack methods for Windows Active Directory.

Updated: 3 days, 18 hours ago
0 stars 0 fork 0 watcher
Born at : Oct. 4, 2024, 3:45 a.m. This repo has been linked 10 different CVEs too.

None

Python C Shell PHP PowerShell ASP.NET

Updated: 4 days, 5 hours ago
0 stars 0 fork 0 watcher
Born at : Oct. 1, 2024, 2:21 p.m. This repo has been linked 66 different CVEs too.

None

Updated: 1 week, 6 days ago
0 stars 0 fork 0 watcher
Born at : Sept. 24, 2024, 5:54 p.m. This repo has been linked 2 different CVEs too.

A comprehensive tool for categorizing TryHackMe rooms, including details such as difficulty, room type, subscription status, and much more, to enhance user experience in cybersecurity training.

Updated: 1 week, 6 days ago
1 stars 0 fork 0 watcher
Born at : Sept. 22, 2024, 1:03 p.m. This repo has been linked 6 different CVEs too.

None

Python

Updated: 2 weeks, 4 days ago
0 stars 0 fork 0 watcher
Born at : Sept. 16, 2024, 7:03 a.m. This repo has been linked 1 different CVEs too.

Principales Ataques para desarrollar el servicio

Updated: 1 month ago
0 stars 0 fork 0 watcher
Born at : Sept. 3, 2024, 7:41 a.m. This repo has been linked 7 different CVEs too.

None

PowerShell Python

Updated: 1 month, 4 weeks ago
0 stars 0 fork 0 watcher
Born at : Aug. 9, 2024, 7:40 a.m. This repo has been linked 1 different CVEs too.

None

Updated: 2 months, 2 weeks ago
0 stars 0 fork 0 watcher
Born at : July 22, 2024, 12:40 p.m. This repo has been linked 2 different CVEs too.

CVE-Data-Fetching-and-Storage-Application

Python

Updated: 2 months, 2 weeks ago
1 stars 0 fork 0 watcher
Born at : July 18, 2024, 5:26 p.m. This repo has been linked 1 different CVEs too.

None

Python

Updated: 2 months, 3 weeks ago
0 stars 0 fork 0 watcher
Born at : July 14, 2024, 4:07 p.m. This repo has been linked 2 different CVEs too.

None

Python CSS JavaScript HTML Dockerfile

Updated: 1 week, 4 days ago
0 stars 0 fork 0 watcher
Born at : July 7, 2024, 7:13 a.m. This repo has been linked 2 different CVEs too.

None

JavaScript

Updated: 3 months ago
0 stars 0 fork 0 watcher
Born at : July 5, 2024, 5:47 p.m. This repo has been linked 2 different CVEs too.

None

Updated: 3 months, 1 week ago
0 stars 0 fork 0 watcher
Born at : June 25, 2024, 2:30 a.m. This repo has been linked 3 different CVEs too.

None

Updated: 3 months, 3 weeks ago
0 stars 0 fork 0 watcher
Born at : June 15, 2024, 9:30 p.m. This repo has been linked 10 different CVEs too.

None

C++ C

Updated: 3 months, 3 weeks ago
0 stars 0 fork 0 watcher
Born at : June 12, 2024, 12:26 a.m. This repo has been linked 1 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-34527 vulnerability anywhere in the article.

  • Cybersecurity News
ZeroLogon to NoPac Vulnerability: Black Basta Group’s Exploit Arsenal Revealed

Desktop background on victim’s system after encryption | Image: QualysQualys has released a comprehensive report shedding light on the Black Basta ransomware, a highly disruptive threat that has wreak ... Read more

Published Date: Sep 22, 2024 (2 weeks, 1 day ago)

The following table lists the changes that have been made to the CVE-2021-34527 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Modified Analysis by [email protected]

    Feb. 02, 2024

    Action Type Old Value New Value
    Changed CPE Configuration OR *cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:21h1:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:* *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:-:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2016:20h2:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:* OR *cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.10240.18969 *cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.14393.4470 *cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.17763.2029 *cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.19042.1083 *cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.19044.1415 *cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.19045.2251 *cpe:2.3:o:microsoft:windows_11_21h2:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.22000.318 *cpe:2.3:o:microsoft:windows_11_22h2:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.22621.674 *cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:* *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:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.14393.4470 *cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.17763.2029 *cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.20348.230 *cpe:2.3:o:microsoft:windows_server_20h2:*:*:*:*:*:*:*:* versions up to (excluding) 10.0.19042.1083
  • CVE Modified by [email protected]

    Dec. 28, 2023

    Action Type Old Value New Value
    Changed Description Windows Print Spooler Remote Code Execution Vulnerability <p>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.</p> <p>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.</p> <p>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 (<strong>Note</strong>: 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):</p> <ul> <li>HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Printers\PointAndPrint</li> <li>NoWarningNoElevationOnInstall = 0 (DWORD) or not defined (default setting)</li> <li>UpdatePromptSettings = 0 (DWORD) or not defined (default setting)</li> </ul> <p><strong>Having NoWarningNoElevationOnInstall set to 1 makes your system vulnerable by design.</strong></p> <p>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 <a href="https://support.microsoft.com/topic/31b91c02-05bc-4ada-a7ea-183b129578a7">KB5005010: Restricting installation of new printer drivers after applying the July 6, 2021 updates</a>.</p> <p>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.</p>
    Added CVSS V3.1 Microsoft Corporation AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
  • Modified Analysis by [email protected]

    Jul. 02, 2022

    Action Type Old Value New Value
    Changed Reference Type http://packetstormsecurity.com/files/167261/Print-Spooler-Remote-DLL-Injection.html No Types Assigned http://packetstormsecurity.com/files/167261/Print-Spooler-Remote-DLL-Injection.html Exploit, Third Party Advisory, VDB Entry
  • CVE Modified by [email protected]

    May. 25, 2022

    Action Type Old Value New Value
    Added Reference http://packetstormsecurity.com/files/167261/Print-Spooler-Remote-DLL-Injection.html [No Types Assigned]
  • Modified Analysis by [email protected]

    Sep. 20, 2021

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Jul. 14, 2021

    Action Type Old Value New Value
    Removed Reference https://www.kb.cert.org/vuls/id/383432 [No Types Assigned]
  • CVE Modified by [email protected]

    Jul. 08, 2021

    Action Type Old Value New Value
    Added Reference https://www.kb.cert.org/vuls/id/383432 [No Types Assigned]
  • Initial Analysis by [email protected]

    Jul. 07, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:L/Au:S/C:C/I:C/A:C)
    Added CVSS V3.1 NIST AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Changed Reference Type https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34527 No Types Assigned https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34527 Mitigation, Patch, Vendor Advisory
    Added CWE NIST CWE-269
    Added CPE Configuration OR *cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:21h1:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:* *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:-:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2016:20h2:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:* *cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-34527 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-34527 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

96.73 }} -0.06%

score

0.99699

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability