{"cve":"CVE-2021-43040","nvd":{"published":"2021-12-06T04:15:07.457","modified":"2026-06-17T04:10:25.130","status":"Modified","description":"An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. The privileged vaultServer could be leveraged to create arbitrary writable files, leading to privilege escalation.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":[],"references":["https://helpdesk.kaseya.com/hc/en-gb/articles/4412762258961","https://www.cyberonesecurity.com/blog/exploiting-kaseya-unitrends-backup-appliance-part-1","https://www.cyberonesecurity.com/blog/exploiting-kaseya-unitrends-backup-appliance-part-2","https://helpdesk.kaseya.com/hc/en-gb/articles/4412762258961","https://www.cyberonesecurity.com/blog/exploiting-kaseya-unitrends-backup-appliance-part-1"],"products":["kaseya:unitrends_backup"],"source":"nvd","synced_at":"2026-10-19T21:25:41.256909649+00:00"},"epss":{"cve":"CVE-2021-43040","score":0.01827,"percentile":0.78835,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}