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CVE-2021-34527 CISA KEV · Actively exploitedLinked to ransomware

Windows Print Spooler Remote Code Execution Vulnerability

CVSS score

8.8

EPSS probability

%99.8

Risk score

17.6

Published

5 y ago

Official patch verified

Etkilenen ürün ve sürüm için yayımlanan güvenlik güncellemesini uygulayın.

Impact on My Inventory

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Vulnerability description

DayBreach CVE AI Research

CVE-2021-34527 has vendor, distribution, patch and security-source records on file. We can compare them and prepare an explanation linked to the evidence.

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.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2021-34527 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1microsoftWindows 10 Version 1507 View
2microsoftWindows 10 Version 1607 View
3microsoftWindows 10 Version 1809 View
4microsoftWindows 10 Version 1809 View
5microsoftWindows 10 Version 20H2 View
6microsoftWindows 10 Version 21H2 View
7microsoftWindows 10 Version 22H2 View
8microsoftWindows 11 version 21H2 View
9microsoftWindows 11 version 22H2 View
10microsoftWindows 8.1 View
11microsoftWindows Server 2008 R2 Service Pack 1 View
12microsoftWindows Server 2008 R2 Service Pack 1 (Server Core installation) View
13microsoftWindows Server 2008 Service Pack 2 View
14microsoftWindows Server 2008 Service Pack 2 (Server Core installation) View
15microsoftwindows server 2012 View
16microsoftWindows Server 2012 (Server Core installation) View
17microsoftWindows Server 2012 R2 View
18microsoftWindows Server 2012 R2 (Server Core installation) View
19microsoftwindows server 2016 View
20microsoftWindows Server 2016 (Server Core installation) View
21microsoftwindows server 2019 View
22microsoftWindows Server 2019 (Server Core installation) View
23microsoftwindows server 2022 View
24microsoftWindows Server version 20H2 View
25microsoftwindows 10 1507 View
26microsoftwindows 10 1607 View
27microsoftwindows 10 1809 View
28microsoftwindows 10 20h2 View
29microsoftwindows 10 21h2 View
30microsoftwindows 10 22h2 View
31microsoftwindows 11 21h2 View
32microsoftwindows 11 22h2 View
33microsoftwindows rt 8.1 View
34microsoftwindows server 2008 View
35microsoftwindows server 2008 View
36microsoftwindows server 2012 View
37microsoftwindows server 2012 View
38microsoftwindows server 2016 View
39microsoftwindows server 2019 View
40microsoftwindows server 2022 View
41microsoftwindows server 20h2 View
Total affected vendors: 1|Products: 41

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
9.0CVSS V2—AV:N/AC:L/Au:S/C:C/I:C/A:CNVD
8.8CVSS V31HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HNVD
8.8CVSS V3_1HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:CCVE CNA

Patch and Remediation Guide

Solution & Remediation Advisory

Patch verified

5 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

nvd

NVD tarafından Patch olarak etiketlenmiş referans

Open source
nvd

NVD tarafından Patch olarak etiketlenmiş referans

Open source
cvelist

Windows Print Spooler Remote Code Execution Vulnerability

Open source
reference

Windows Print Spooler Remote Code Execution Vulnerability

Open source
reference

Yama veya çözüm referansı

Open source
canonical

Apply updates per vendor instructions.

Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Apply the official update named in the evidence only to the matching product and version.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

CVE-2021-34527 : the database holds 3 public PoC/exploit sources for it. For direct links to the sources, open the Public Exploits tab.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises 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.

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsLow
UserGerekmiyor

Official Sources and Advisories

CVSS Vector Radar Chart

8.8 / 10
Attack VectorNetworkComplexityLowPrivilegesLowUser Interact.NoneConfidentialityLowIntegrityNoneAvailabilityHigh

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow privileges
User InteractionNone required
Confidentiality (Gizlilik)Low
Integrity (Bütünlük)None
Availability (Erişilebilirlik)High

Yama doğrulandı

5 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

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