8.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
9.3 High
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:C/I:C/A:C
Microsoft has released out-of-band security updates to address a remote code execution (RCE) vulnerability—known as PrintNightmare (CVE-2021-34527)—in the Windows Print spooler service. According to the CERT Coordination Center (CERT/CC), “The Microsoft Windows Print Spooler service fails to restrict access to functionality that allows users to add printers and related drivers, which can allow a remote authenticated attacker to execute arbitrary code with SYSTEM privileges on a vulnerable system.”
The updates are cumulative and contain all previous fixes as well as protections for CVE-2021-1675. The updates do not include Windows 10 version 1607, Windows Server 2012, or Windows Server 2016—Microsoft states updates for these versions are forthcoming. Note: According to CERT/CC, “the Microsoft update for CVE-2021-34527 only appears to address the Remote Code Execution (RCE via SMB and RPC) variants of the PrintNightmare, and not the Local Privilege Escalation (LPE) variant.” See CERT/CC Vulnerability Note VU #383432 for workarounds for the LPE variant.
CISA encourages users and administrators to review the Microsoft Security Updates as well as CERT/CC Vulnerability Note VU #383432 and apply the necessary updates or workarounds. For additional background, see CISA’s initial Current Activity on PrintNightmare.
This product is provided subject to this Notification and this Privacy & Use policy.
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8.8 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
9.3 High
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:C/I:C/A:C