CVE-2021-43042
An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. A buffer overflow...
An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. A buffer overflow existed in the vaultServer component. This was exploitable by a remote unauthenticated attacker.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. A buffer overflow existed in the vaultServer component. This was exploitable by a remote unauthenticated attacker.
- Record
CVE-2021-43042- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-120
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. A buffer overflow existed in the vaultServer component. This was exploitable by a remote unauthenticated attacker.
- Record
CVE-2021-43042- Updated
- 2026-11-02
EUVDEUVD-2021-29996 No score
An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. A buffer overflow existed in the vaultServer component. This was exploitable by a remote unauthenticated attacker.
- Record
EUVD-2021-29996- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-8xcf-7jjj-p7rh
An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. A buffer overflow...
An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. A buffer overflow existed in the vaultServer component. This was exploitable by a remote unauthenticated attacker.
- Record
GHSA-8xcf-7jjj-p7rh- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-43042 is a critical vulnerability (CVSS 9.8) in Kaseya Unitrends Backup, published December 6, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.99%, the 87th percentile. No source names a fixed version.