Cyber Resilience

CVE-2021-43033

CriticalPublic PoCRCE

Published: 06 December 2021

Published
06 December 2021
Modified
21 November 2024
KEV Added
—
Patch
—
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.1095 93.6th percentile
Risk Priority 26 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-43033 is a critical-severity OS Command Injection (CWE-78) vulnerability in Kaseya Unitrends Backup. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 6.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. Multiple functions in the bpserverd daemon were vulnerable to arbitrary remote code execution as root. The vulnerability was caused by untrusted input (received by the server) being passed to…

more

system calls.

CWE(s)
CWE-78

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

kaseya
unitrends backup
10.0 — 10.5.5

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-27 Platform-independent Applications
addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

SI-10 Information Input Validation
addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

References