{"id":"CVE-2022-24521","published":"2022-04-15T19:15:11Z","modified":"2026-06-17T04:32:02Z","title":"Microsoft Windows CLFS Driver Privilege Escalation Vulnerability","vendor":"Microsoft","product":"Windows","tier":"core","eol":null,"description":{"text":"Windows Common Log File System Driver Elevation of Privilege Vulnerability","provenance":"source","from":"NVD"},"summary":{"text":"The flaw is in the Common Log File System (CLFS) driver of Microsoft Windows, where improper validation of input leads to an out-of-bounds write. An attacker who already has low-privileged local access, with no user interaction required, can exploit it to elevate their privileges on the affected Windows system.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:06:35Z"},"cvss":{"score":7.8,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.07134,"percentile":0.94246,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2022-04-13","dueDate":"2022-05-04","ransomware":true,"requiredAction":"Apply updates per vendor instructions.","notes":"https://nvd.nist.gov/vuln/detail/CVE-2022-24521","provenance":"source"},"vulncheckKev":{"dateAdded":"2022-04-12","exploitedFirstSeen":"2022-04-12","ransomware":true,"evidence":[{"url":"https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2022-Apr","date":"2022-04-12"},{"url":"https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit","date":"2022-04-12"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2022-04-13"},{"url":"https://www.covertswarm.com/post/multiple-windows-zero-days-cve-2022-24521-cve-2022-26904-and-cve-2022-26809","date":"2022-04-14"},{"url":"https://unit42.paloaltonetworks.com/cuba-ransomware-tropical-scorpius/","date":"2022-08-09"},{"url":"https://www.bleepingcomputer.com/news/security/cisco-hacked-by-yanluowang-ransomware-gang-28gb-allegedly-stolen/","date":"2022-08-10"},{"url":"https://securelist.com/it-threat-evolution-in-q2-2022-non-mobile-statistics/107133/","date":"2022-08-15"},{"url":"https://securelist.com/ransomware-updates-1-day-exploits/107291/","date":"2022-08-24"},{"url":"https://www.microsoft.com/en-us/security/blog/2022/10/25/dev-0832-vice-society-opportunistic-ransomware-campaigns-impacting-us-education-sector/","date":"2022-10-25"},{"url":"https://www.cisa.gov/uscert/sites/default/files/publications/aa22-335a-stopransomware-cuba-ransomware.pdf","date":"2022-12-01"}],"evidenceTotal":30,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-787","name":"Out-of-bounds Write"},{"id":"CWE-1285","name":"Improper Validation of Specified Index, Position, or Offset in Input"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-24521","tags":["Patch","Vendor Advisory"]},{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-24521","tags":["Patch","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-24521","tags":["US Government Resource"]}],"techniques":[{"id":"T1078","name":"Valid Accounts","tactics":["initial-access","persistence","privilege-escalation","stealth"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Privilege Escalation","mappingType":"exploitation_technique","evidence":[],"comment":"This vulnerability is exploited by an attacker who has already obtained access to a target system to execute code. The vulnerability lies in the Common Log File System (CLFS) driver, specifically in the `CClfsBaseFilePersisted::LoadContainerQ()` function, due to a logic bug in handling container context objects. This vulnerability has been exploited by threat actors to gain elevated privileges on Windows systems. Attackers leveraged this flaw to execute arbitrary code with system-level privileges, allowing them to manipulate system processes and deploy additional malware to perform further malicious activities.\n\nThe exploit in question is actively being used in the wild, primarily in ransomware campaigns. It involves corrupting the `pContainer` field of a container context object with a user-mode address by using malformed BLF files. Once the vulnerability is exploited, attackers can manipulate memory to execute code with elevated privileges. This allows them to achieve their objectives, such as stealing the System token and gaining full control over the compromised system.","confidence":"high"},{"id":"T1068","name":"Exploitation for Privilege Escalation","tactics":["privilege-escalation"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Privilege Escalation","mappingType":"primary_impact","evidence":[],"comment":"This vulnerability is exploited by an attacker who has already obtained access to a target system to execute code. The vulnerability lies in the Common Log File System (CLFS) driver, specifically in the `CClfsBaseFilePersisted::LoadContainerQ()` function, due to a logic bug in handling container context objects. This vulnerability has been exploited by threat actors to gain elevated privileges on Windows systems. Attackers leveraged this flaw to execute arbitrary code with system-level privileges, allowing them to manipulate system processes and deploy additional malware to perform further malicious activities.\n\nThe exploit in question is actively being used in the wild, primarily in ransomware campaigns. It involves corrupting the `pContainer` field of a container context object with a user-mode address by using malformed BLF files. Once the vulnerability is exploited, attackers can manipulate memory to execute code with elevated privileges. This allows them to achieve their objectives, such as stealing the System token and gaining full control over the compromised system.","confidence":"high"},{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Privilege Escalation","mappingType":"secondary_impact","evidence":[],"comment":"This vulnerability is exploited by an attacker who has already obtained access to a target system to execute code. The vulnerability lies in the Common Log File System (CLFS) driver, specifically in the `CClfsBaseFilePersisted::LoadContainerQ()` function, due to a logic bug in handling container context objects. This vulnerability has been exploited by threat actors to gain elevated privileges on Windows systems. Attackers leveraged this flaw to execute arbitrary code with system-level privileges, allowing them to manipulate system processes and deploy additional malware to perform further malicious activities.\n\nThe exploit in question is actively being used in the wild, primarily in ransomware campaigns. It involves corrupting the `pContainer` field of a container context object with a user-mode address by using malformed BLF files. Once the vulnerability is exploited, attackers can manipulate memory to execute code with elevated privileges. This allows them to achieve their objectives, such as stealing the System token and gaining full control over the compromised system.","confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2022-29401","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2022-29401","exploited":true,"exploitedSince":"2022-04-13","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":1,"skipped":0,"earliest":"2026-02-19","earliestUrl":"https://github.com/uname1able/CVE-2022-24521","repos":[{"name":"uname1able/CVE-2022-24521","url":"https://github.com/uname1able/CVE-2022-24521","stars":0,"created":"2026-02-19"}]},"first":{"date":"2026-02-19","source":"PoC-in-GitHub","url":"https://github.com/uname1able/CVE-2022-24521"},"provenance":"source"},"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1078"],"provenance":"source"},{"stage":"primary","techniques":["T1068"],"provenance":"source"},{"stage":"secondary","techniques":["T1059"],"provenance":"source"}],"timeline":[{"date":"2022-04-12","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2022-Apr","provenance":"source"},{"date":"2022-04-13","kind":"kev","label":"Added to CISA KEV (known ransomware use)","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2022-04-13","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2022-29401","provenance":"source"},{"date":"2022-04-15","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-24521","provenance":"source"},{"date":"2026-02-19","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub","url":"https://github.com/uname1able/CVE-2022-24521","provenance":"source"}],"speed":{"daysToPublicExploit":1406,"firstExploitFrom":"PoC-in-GitHub","daysToKev":null},"priority":{"score":77.3,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 1661 days ago"},{"name":"Known ransomware use","points":10.0,"detail":"CISA KEV and VulnCheck KEV: Known"},{"name":"EPSS percentile","points":18.85,"detail":"percentile 0.9425"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 PoC-in-GitHub repo"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":5.46,"detail":"base score 7.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]},"lineage":{"familyId":"fam-class-microsoft-windows-cwe-787"}}