SystemNightmare by GentilKiwi - External Printer Mapped - CVE-2021-1675 / CVE-2021-34527 (via security)
- Product
- windows
- Service
- security
- Author
- HuntRule
- Published
- 2026-09-01
- Updated
- 2026-09-01
ATT&CK techniques
Execution → Defense EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule detects exploit the PrintNightmare vulnerability by abusing the Windows print spooler using the service exposed by Gentilkiwi.
Reporting behind it
- attack.mitre.orghttps://attack.mitre.org/techniques/T1574/002/
- attack.mitre.orghttps://attack.mitre.org/techniques/T1547/010/
- github.comhttps://github.com/GossiTheDog/SystemNightmare
- github.comhttps://github.com/outflanknl/PrintNightmare
- github.comhttps://github.com/cube0x0/CVE-2021-1675
- theregister.comhttps://www.theregister.com/2021/09/21/microsoft_printnightmare/
- exabeam.comhttps://www.exabeam.com/information-security/detecting-the-printnightmare-cve-2021-1675-34527-vulnerability-using-exabeam/
- ultimatewindowssecurity.comhttps://www.ultimatewindowssecurity.com/securitylog/encyclopedia/event.aspx?eventID=4648
- ultimatewindowssecurity.comhttps://www.ultimatewindowssecurity.com/securitylog/encyclopedia/event.aspx?eventID=4688
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
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