🇰🇷 한글 설명
Windows Print Spooler 서비스가 권한이 있는 파일 작업을 부적절하게 수행하여 발생하는 원격 코드 실행 취약점입니다. 공격자가 이를 악용할 경우 SYSTEM 권한으로 임의의 코드를 실행하여 프로그램을 설치하거나 데이터를 조작하고 새로운 계정을 생성할 수 있습니다.
💡 쉬운 설명
윈도우의 프린터 관리 기능에 결함이 있어, 해커가 멀리서 내 컴퓨터를 마음대로 조종할 수 있는 위험한 보안 구멍입니다. 이 구멍을 통해 해커는 관리자 권한을 뺏어 파일을 지우거나 새로운 사용자를 만들 수 있습니다.
🇺🇸 원문 (English)
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.
📍 영향받는 시스템
Windows Server 2012, Windows Server 2016, Windows 10 (Version 1607) 및 관련 Print Spooler 서비스 사용 시스템
⚔️ 공격 벡터
네트워크를 통한 원격 공격을 통해 Windows Print Spooler 서비스의 취약점을 악용하여 SYSTEM 권한 획득
🛡️ 대응 방법
최신 보안 업데이트를 설치하고, 레지스트리 설정(NoWarningNoElevationOnInstall, UpdatePromptSettings)이 0이거나 정의되지 않았는지 확인합니다.
🔧 검증 코드
명령어 결과에서 NoWarningNoElevationOnInstall 값이 1로 나오면 취약한 상태이며, 0이거나 항목이 없어야 안전합니다.
reg query "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Printers\PointAndPrint" /v NoWarningNoElevationOnInstall