[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fUSe0moPUQkq11TnpPTGYXQOVb7BH38ho5dFFXECXeUM":3},{"article":4,"iocs":41,"watch_terms":46,"solutions":47,"lesson":142},{"id":5,"title":6,"slug":7,"summary":8,"ai_summary":9,"brief":10,"url":11,"image_url":12,"published_at":13,"ingested_at":14,"relevance_score":15,"entities":16,"category_id":30,"category":31,"article_tags":35},"32b0b7e2-b857-411e-85c1-45010c70da7b","SignDrop Windows CLFS Zero-Day Gives SYSTEM Access","signdrop-windows-clfs-zero-day-gives-system-access-0ce4b0","An unpatched Windows zero-day, SignDrop, abuses the CLFS authentication feature to escalate a standard user to SYSTEM. No CVE and no patch yet.","A researcher known as Chaotic Eclipse published a working exploit for SignDrop, an unpatched Windows zero-day local privilege-escalation flaw in clfs.sys that allows a standard user to gain SYSTEM privileges by abusing Microsoft's CLFS authentication mitigation. The flaw exploits how the kernel creates .cnpf signature files, coercing privileged processes like Microsoft Defender to write the file as SYSTEM with inherited permissions. No CVE, CVSS score, or patch exists as of November 11, 2026, and the researcher posted the proof-of-concept on GitHub without coordinated disclosure.","SignDrop Windows CLFS zero-day abuses kernel authentication mitigation to escalate standard user to SYSTEM.","https:\u002F\u002Fwww.cyberkendra.com\u002F2026\u002F11\u002Fsigndrop-windows-clfs-zero-day-system-exploit.html","https:\u002F\u002Fwww.cyberkendra.com\u002Fwp-content\u002Fuploads\u002F2026\u002F11\u002FSignDrop.webp","2026-11-11T16:40:06+00:00","2026-11-11T17:00:27.252647+00:00",9,[17,20,23,25,27],{"name":18,"type":19},"Chaotic Eclipse","threat_actor",{"name":21,"type":22},"Windows 11","product",{"name":24,"type":22},"Windows Server 2025",{"name":26,"type":22},"Microsoft Defender",{"name":28,"type":29},"CLFS (Common Log File System)","technology","574f766a-fb3f-487c-8d2c-0720ae75471b",{"id":30,"icon":32,"name":33,"slug":34},null,"Zero-day","zero-day",[36],{"category":37},{"id":38,"icon":32,"name":39,"slug":40},"80544778-fabb-4dcd-aa35-17492e5dcf4f","Vulnerabilities","vulnerabilities",[42],{"type":43,"value":44,"context":45},"malware","SignDrop","Windows CLFS zero-day local privilege escalation exploit",[21,24,26],{"controls":48,"vendors":135},[49,77,106],{"slug":50,"name":51,"problem":52,"products":53},"privileged-access-management","Privileged access management (PAM)","Admin accounts stop being one stolen password away from control of everything.",[54,62,69],{"vendor_slug":55,"vendor_name":56,"vendor_logo":57,"product_slug":58,"product_name":59,"url":60,"description":61},"delinea","Delinea","\u002Fvendor-logos\u002Fdelinea.png","secret-server","Delinea Secret Server","https:\u002F\u002Fdelinea.com\u002Fproducts\u002Fsecret-server","Vault for privileged credentials with discovery, rotation and session recording.",{"vendor_slug":63,"vendor_name":64,"vendor_logo":65,"product_slug":50,"product_name":66,"url":67,"description":68},"threatlocker","ThreatLocker","\u002Fvendor-logos\u002Fthreatlocker.png","Privileged Access Management","https:\u002F\u002Fwww.threatlocker.com\u002Fcapabilities\u002Fprivileged-access-management","Gives elevated rights to specific applications only where needed, so users do not need local admin accounts.",{"vendor_slug":70,"vendor_name":71,"vendor_logo":72,"product_slug":73,"product_name":74,"url":75,"description":76},"beyondtrust","BeyondTrust","\u002Fvendor-logos\u002Fbeyondtrust.png","password-safe","BeyondTrust Password Safe","https:\u002F\u002Fwww.beyondtrust.com\u002Fproducts\u002Fpassword-safe","Privileged password and session management.",{"slug":78,"name":79,"problem":80,"products":81},"patch-management","Automated patch management","Known holes get closed in days, not months.",[82,90,98],{"vendor_slug":83,"vendor_name":84,"vendor_logo":85,"product_slug":86,"product_name":87,"url":88,"description":89},"ivanti","Ivanti","\u002Fvendor-logos\u002Fivanti.png","neurons-patch-management","Ivanti Neurons for Patch Management","https:\u002F\u002Fwww.ivanti.com\u002Fproducts\u002Fivanti-neurons-for-patch-management","Risk-based patch management for operating systems and third-party applications.",{"vendor_slug":91,"vendor_name":92,"vendor_logo":93,"product_slug":94,"product_name":95,"url":96,"description":97},"action1","Action1","\u002Fvendor-logos\u002Faction1.png","action1-patch-management","Action1 Patch Management","https:\u002F\u002Fwww.action1.com\u002F","Cloud-native patch management for Windows, macOS and third-party applications.",{"vendor_slug":99,"vendor_name":100,"vendor_logo":101,"product_slug":102,"product_name":103,"url":104,"description":105},"ninjaone","NinjaOne","\u002Fvendor-logos\u002Fninjaone.png","ninjaone-patch-management","NinjaOne Patch Management","https:\u002F\u002Fwww.ninjaone.com\u002Fpatch-management\u002F","Automated patching of operating systems and third-party applications from the cloud.",{"slug":107,"name":108,"problem":109,"products":110},"endpoint-detection-response","Endpoint detection and response (EDR and XDR)","Malware and hands-on-keyboard attackers on laptops and servers get spotted and stopped.",[111,119,127],{"vendor_slug":112,"vendor_name":113,"vendor_logo":114,"product_slug":115,"product_name":116,"url":117,"description":118},"bitdefender","Bitdefender","\u002Fvendor-logos\u002Fbitdefender.png","gravityzone","GravityZone","https:\u002F\u002Fwww.bitdefender.com\u002Fen-us\u002Fbusiness\u002Fgravityzone-platform\u002F","Endpoint protection, detection and response platform.",{"vendor_slug":120,"vendor_name":121,"vendor_logo":122,"product_slug":123,"product_name":124,"url":125,"description":126},"huntress","Huntress","\u002Fvendor-logos\u002Fhuntress.png","managed-edr","Huntress Managed EDR","https:\u002F\u002Fwww.huntress.com\u002Fplatform\u002Fmanaged-edr","Endpoint detection and response monitored around the clock by Huntress analysts.",{"vendor_slug":128,"vendor_name":129,"vendor_logo":130,"product_slug":131,"product_name":132,"url":133,"description":134},"elastic","Elastic","\u002Fvendor-logos\u002Felastic.png","elastic-security","Elastic Security","https:\u002F\u002Fwww.elastic.co\u002Fsecurity","SIEM and endpoint security built on Elasticsearch, with open detection rules.",[136],{"slug":137,"name":138,"logo_path":139,"roles":140},"microsoft","Microsoft","\u002Fvendor-logos\u002Fmicrosoft.png",[141],"affected",{"slug":143,"title":144,"body":145,"framework_refs":146,"framework_notes":152},"unpatched-windows-clfs-zero-day-enables-full-system-privilege-escalation","Unpatched Windows CLFS Zero-Day Enables Full SYSTEM Privilege Escalation","A publicly disclosed, unpatched local privilege-escalation vulnerability in Windows' Common Log File System (clfs.sys) allows any standard user to attain SYSTEM-level access by abusing how privileged processes like Microsoft Defender inherit file permissions when creating CLFS signature files. With no CVE, no patch, and a working proof-of-concept posted publicly on GitHub without coordinated disclosure, every unmitigated Windows system is now exposed to trivial privilege escalation. This matters because SYSTEM access effectively gives an attacker complete control over the host — enabling credential theft, lateral movement, and ransomware deployment. The lack of responsible disclosure denied Microsoft the opportunity to prepare mitigations before exploitation guidance became widely available.",[147,148,149,150,151],"MITRE ATT&CK T1068: Exploitation for Privilege Escalation","CIS Control 7: Continuous Vulnerability Management (v8)","NIST SP 800-53 SI-2: Flaw Remediation","NIS2 Article 21(2)(e)","NIST CSF 2.0 DE.CM-01: Networks and network services are monitored to find potentially adverse events",{"NIS2 Article 21(2)(e)":153,"NIST SP 800-53 SI-2: Flaw Remediation":154,"CIS Control 7: Continuous Vulnerability Management (v8)":155,"MITRE ATT&CK T1068: Exploitation for Privilege Escalation":156,"NIST CSF 2.0 DE.CM-01: Networks and network services are monitored to find potentially adverse events":157},"This point covers vulnerability handling and disclosure practices, directly relevant because the researcher bypassed coordinated disclosure, leaving organizations with no vendor guidance or patch to act on.","SI-2 requires identifying, reporting, and correcting system flaws; the absence of any patch or vendor acknowledgment means affected organizations must implement compensating controls while awaiting remediation.","CIS Control 7 requires organizations to track and remediate vulnerabilities continuously, including zero-days without CVEs, which would prompt interim mitigations when no patch exists.","This technique directly describes exploiting a software vulnerability — here the CLFS kernel flaw — to gain elevated SYSTEM privileges from a standard user context.","Detecting exploitation of this zero-day before a patch exists depends entirely on runtime monitoring of anomalous privilege changes and CLFS file operations on endpoints."]