{"schemaVersion":3,"id":"CVE-2021-3543","aliases":["UBUNTU-CVE-2021-3543","DEBIAN-CVE-2021-3543"],"status":"published","duplicateOf":null,"title":null,"description":"A flaw null pointer dereference in the Nitro Enclaves kernel driver was found in the way that Enclaves VMs forces closures on the enclave file descriptor. A local user of a host machine could use this flaw to crash the system or escalate their privileges on the system.","dates":{"published":"2021-06-01T13:20:34.000Z","modified":"2024-08-03T17:01:07.979Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.2,"severity":"high","version":"2.0","versionLabel":"v2.0","source":"NVD","vector":"AV:L/AC:L/Au:N/C:C/I:C/A:C","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"OSV · Ubuntu","score":6.7,"severity":"medium","vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","exploitability":2.1,"impact":9.8,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Debian","score":6.7,"severity":"medium","vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","exploitability":2.1,"impact":9.8,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":6.7,"severity":"medium","vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","exploitability":null,"impact":null,"computed":false},{"version":"2.0","versionLabel":"v2.0","source":"NVD","score":7.2,"severity":"high","vector":"AV:L/AC:L/Au:N/C:C/I:C/A:C","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00301,"percentile":0.21486,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":0,"baselineDate":"2026-09-19T00:00:00.000Z","baselineScore":0.00301},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00301,"percentile":0.21486}],"last30":[{"date":"2026-09-19T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00301,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00301,"percentile":0.21486}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-416","name":"Use After Free","description":"The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory \"belongs\" to the code that operates on the new pointer.","type":"weakness","status":"Stable","abstraction":"Variant","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/416.html"},{"id":"CWE-476","name":"NULL Pointer Dereference","description":"The product dereferences a pointer that it expects to be valid but is NULL.","type":"weakness","status":"Stable","abstraction":"Base","likelihoodOfExploit":"Medium","url":"https://cwe.mitre.org/data/definitions/476.html"}],"affected":[{"vendor":"debian","product":"linux","name":"linux","label":"linux","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/linux","purlType":"deb","versions":[{"text":"< 5.10.38-1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 5.10.38-1","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-aws","name":"linux-aws","label":"linux-aws","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-aws","purlType":"deb","versions":[{"text":"< 5.4.0-1064.67","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 5.4.0-1064.67","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-aws-5.0","name":"linux-aws-5.0","label":"linux-aws-5.0","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-aws-5.0","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-aws-5.3","name":"linux-aws-5.3","label":"linux-aws-5.3","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-aws-5.3","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-aws-5.4","name":"linux-aws-5.4","label":"linux-aws-5.4","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-aws-5.4","purlType":"deb","versions":[{"text":"< 5.4.0-1064.67~18.04.1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 5.4.0-1064.67~18.04.1","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-aws-5.8","name":"linux-aws-5.8","label":"linux-aws-5.8","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-aws-5.8","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-azure","name":"linux-azure","label":"linux-azure","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-azure","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-azure-5.3","name":"linux-azure-5.3","label":"linux-azure-5.3","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-azure-5.3","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-azure-edge","name":"linux-azure-edge","label":"linux-azure-edge","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-azure-edge","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-gcp","name":"linux-gcp","label":"linux-gcp","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-gcp","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-gcp-5.3","name":"linux-gcp-5.3","label":"linux-gcp-5.3","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-gcp-5.3","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-gcp-edge","name":"linux-gcp-edge","label":"linux-gcp-edge","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-gcp-edge","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-gke-4.15","name":"linux-gke-4.15","label":"linux-gke-4.15","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-gke-4.15","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-hwe","name":"linux-hwe","label":"linux-hwe","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-hwe","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-hwe-edge","name":"linux-hwe-edge","label":"linux-hwe-edge","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-hwe-edge","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-oem","name":"linux-oem","label":"linux-oem","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-oem","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-oem-5.10","name":"linux-oem-5.10","label":"linux-oem-5.10","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-oem-5.10","purlType":"deb","versions":[{"text":"< 5.10.0-1032.33","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 5.10.0-1032.33","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-oracle-5.0","name":"linux-oracle-5.0","label":"linux-oracle-5.0","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-oracle-5.0","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-oracle-5.3","name":"linux-oracle-5.3","label":"linux-oracle-5.3","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-oracle-5.3","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-raspi2","name":"linux-raspi2","label":"linux-raspi2","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-raspi2","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"linux-riscv","name":"linux-riscv","label":"linux-riscv","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/linux-riscv","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"fedoraproject","product":"fedora","name":"fedora","label":"fedora","ecosystem":null,"cpePart":"o","purl":null,"purlType":null,"versions":[{"text":"34","noFixRecorded":false,"fixedIn":null}],"versionsText":"34","eol":{"isEol":true,"eolDate":"2022-06-07T00:00:00.000Z","matchMethod":"cpe","cycle":{"name":"34","label":"34","eolFrom":"2022-06-07T00:00:00.000Z","isLts":false,"isMaintained":false,"latestVersion":null},"product":{"name":"fedora","label":"Fedora Linux","category":"os"}},"hubHref":"/vendor/fedoraproject/fedora"},{"vendor":"nitro_enclaves_project","product":"nitro_enclaves","name":"nitro enclaves","label":"nitro_enclaves","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 5.10.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 5.10.0","eol":null,"hubHref":"/vendor/nitro_enclaves_project/nitro_enclaves"},{"vendor":"redhat","product":"enterprise_linux","name":"enterprise linux","label":"enterprise_linux","ecosystem":null,"cpePart":"o","purl":null,"purlType":null,"versions":[{"text":"8.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"8.0","eol":{"isEol":false,"eolDate":"2029-05-31T00:00:00.000Z","matchMethod":"cpe","cycle":{"name":"8","label":"8 (Upcoming ELS)","eolFrom":"2029-05-31T00:00:00.000Z","isLts":false,"isMaintained":true,"latestVersion":"8.10"},"product":{"name":"rhel","label":"Red Hat Enterprise Linux","category":"os"}},"hubHref":"/vendor/redhat/enterprise_linux"}],"affectedCount":24,"eol":{"hasEol":true,"count":1},"references":[{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=1953022","label":"bugzilla.redhat.com/show_bug.cgi?id=1953022","hostname":"bugzilla.redhat.com","tags":["X Refsource MISC","Issue Tracking","Third Party Advisory"]},{"url":"https://lore.kernel.org/lkml/20210429165941.27020-2-andraprs%40amazon.com/","label":"lore.kernel.org/lkml/20210429165941.27020-2-andraprs%40amazon.com/","hostname":"lore.kernel.org","tags":["X Refsource MISC"]},{"url":"https://ubuntu.com/security/CVE-2021-3543","label":"ubuntu.com/security/CVE-2021-3543","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://git.kernel.org/linus/f1ce3986baa62cffc3c5be156994de87524bab99","label":"git.kernel.org/linus/f1ce3986baa62cffc3c5be156994de87524bab99","hostname":"git.kernel.org","tags":["REPORT"]},{"url":"https://ubuntu.com/security/notices/USN-4997-1","label":"ubuntu.com/security/notices/USN-4997-1","hostname":"ubuntu.com","tags":["Advisory"]},{"url":"https://ubuntu.com/security/notices/USN-5001-1","label":"ubuntu.com/security/notices/USN-5001-1","hostname":"ubuntu.com","tags":["Advisory"]},{"url":"https://ubuntu.com/security/notices/USN-4997-2","label":"ubuntu.com/security/notices/USN-4997-2","hostname":"ubuntu.com","tags":["Advisory"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-3543","label":"www.cve.org/CVERecord?id=CVE-2021-3543","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-3543","label":"security-tracker.debian.org/tracker/CVE-2021-3543","hostname":"security-tracker.debian.org","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":["RHSA-2021:2168","RHSA-2021:2169","USN-5001-1"],"duplicates":[],"related":["USN-5001-1"]},"timeline":[{"kind":"published","date":"2021-06-01T13:20:34.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2024-08-03T17:01:07.979Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":29,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-20T11:41:33.611Z","stale":false,"partial":false}}