{"api_version":"1","generated_at":"2026-05-05T15:17:43+00:00","cve":"CVE-2021-21787","urls":{"html":"https://cve.report/CVE-2021-21787","api":"https://cve.report/api/cve/CVE-2021-21787.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-21787","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-21787"},"summary":{"title":"CVE-2021-21787","description":"A privilege escalation vulnerability exists in the way IOBit Advanced SystemCare Ultimate 14.2.0.220 driver handles Privileged I/O write requests. During IOCTL 0x9c40a0d8, the first dword passed in the input buffer is the device port to write to and the byte at offset 4 is the value to write via the OUT instruction. The OUT instruction can write one byte to the given I/O device port, potentially leading to escalated privileges of unprivileged users.","state":"PUBLIC","assigner":"talos-cna@cisco.com","published_at":"2021-07-07 17:15:00","updated_at":"2022-07-29 12:58:00"},"problem_types":["NVD-CWE-Other"],"metrics":[],"references":[{"url":"https://talosintelligence.com/vulnerability_reports/TALOS-2021-1254","name":"https://talosintelligence.com/vulnerability_reports/TALOS-2021-1254","refsource":"MISC","tags":[],"title":"TALOS-2021-1254 ||  Cisco Talos Intelligence Group - Comprehensive Threat Intelligence","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-21787","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21787","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2021","cve_id":"21787","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"iobit","cpe5":"advanced_systemcare_ultimate","cpe6":"14.2.0.220","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"data_type":"CVE","data_format":"MITRE","data_version":"4.0","CVE_data_meta":{"ID":"CVE-2021-21787","ASSIGNER":"talos-cna@cisco.com","STATE":"PUBLIC"},"affects":{"vendor":{"vendor_data":[{"vendor_name":"n/a","product":{"product_data":[{"product_name":"Iobit","version":{"version_data":[{"version_value":"IOBit Advanced SystemCare Ultimate 14.2.0.220"}]}}]}}]}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-782: Exposed IOCTL with Insufficient Access Control"}]}]},"references":{"reference_data":[{"refsource":"MISC","name":"https://talosintelligence.com/vulnerability_reports/TALOS-2021-1254","url":"https://talosintelligence.com/vulnerability_reports/TALOS-2021-1254"}]},"description":{"description_data":[{"lang":"eng","value":"A privilege escalation vulnerability exists in the way IOBit Advanced SystemCare Ultimate 14.2.0.220 driver handles Privileged I/O write requests. During IOCTL 0x9c40a0d8, the first dword passed in the input buffer is the device port to write to and the byte at offset 4 is the value to write via the OUT instruction. The OUT instruction can write one byte to the given I/O device port, potentially leading to escalated privileges of unprivileged users."}]},"impact":{"cvss":{"baseScore":8.8,"baseSeverity":"High","vectorString":"CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","version":"3.0"}}},"nvd":{"publishedDate":"2021-07-07 17:15:00","lastModifiedDate":"2022-07-29 12:58:00","problem_types":["NVD-CWE-Other"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseScore":8.8,"baseSeverity":"HIGH"},"exploitabilityScore":2,"impactScore":6},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:L/AC:L/Au:N/C:P/I:P/A:P","accessVector":"LOCAL","accessComplexity":"LOW","authentication":"NONE","confidentialityImpact":"PARTIAL","integrityImpact":"PARTIAL","availabilityImpact":"PARTIAL","baseScore":4.6},"severity":"MEDIUM","exploitabilityScore":3.9,"impactScore":6.4,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:iobit:advanced_systemcare_ultimate:14.2.0.220:*:*:*:*:*:*:*","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"21787","Ordinal":"196476","Title":"CVE-2021-21787","CVE":"CVE-2021-21787","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"21787","Ordinal":"1","NoteData":"A privilege escalation vulnerability exists in the way IOBit Advanced SystemCare Ultimate 14.2.0.220 driver handles Privileged I/O write requests. During IOCTL 0x9c40a0d8, the first dword passed in the input buffer is the device port to write to and the byte at offset 4 is the value to write via the OUT instruction. The OUT instruction can write one byte to the given I/O device port, potentially leading to escalated privileges of unprivileged users.","Type":"Description","Title":null},{"CveYear":"2021","CveId":"21787","Ordinal":"2","NoteData":"2021-07-07","Type":"Other","Title":"Published"},{"CveYear":"2021","CveId":"21787","Ordinal":"3","NoteData":"2021-07-07","Type":"Other","Title":"Modified"}]}}}