CVE-2021-43040
The privileged vaultServer could be leveraged to create arbitrary writable files, leading to privilege escalation.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.83%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.83% probability · 79th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Affected
- kaseya/unitrends backup
- Source
- cve@mitre.org
EPSS 1.8% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://helpdesk.kaseya.com/hc/en-gb/articles/4412762258961Vendor Advisory
- https://www.cyberonesecurity.com/blog/exploiting-kaseya-unitrends-backup-appliance-part-1Exploit, Third Party Advisory
- https://www.cyberonesecurity.com/blog/exploiting-kaseya-unitrends-backup-appliance-part-2Exploit, Third Party Advisory
- https://helpdesk.kaseya.com/hc/en-gb/articles/4412762258961Vendor Advisory
- https://www.cyberonesecurity.com/blog/exploiting-kaseya-unitrends-backup-appliance-part-1Exploit, Third Party Advisory
- https://www.cyberonesecurity.com/blog/exploiting-kaseya-unitrends-backup-appliance-part-2Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.