How severe is CVE-2021-43035?

CVE-2021-43035 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-43035 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43035?

CVE-2021-43035 affects Kaseya Unitrends Backup. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43035?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-43035 published?

CVE-2021-43035 was published on 2021-12-06 and last updated on 2026-06-17.

CVE-2021-43035

CVE-2021-43035 is a critical-severity vulnerability in Kaseya Unitrends Backup with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-89.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 3% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-89
Affected product: Kaseya Unitrends Backup
Published: 2021-12-06
Last modified: 2026-06-17

Description

An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. Two unauthenticated SQL injection vulnerabilities were discovered, allowing arbitrary SQL queries to be injected and executed under the postgres superuser account. Remote code execution was possible, leading to full access to the postgres user account.

Frequently asked questions

What is CVE-2021-43035?: An issue was discovered in Kaseya Unitrends Backup Appliance before 10.5.5. Two unauthenticated SQL injection vulnerabilities were discovered, allowing arbitrary SQL queries to be injected and executed under the postgres superuser account. Remote code execution was possible, leading to full access to the postgres user account.
How severe is CVE-2021-43035?: CVE-2021-43035 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-43035 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43035?: CVE-2021-43035 affects Kaseya Unitrends Backup. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43035?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-43035 published?: CVE-2021-43035 was published on 2021-12-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:kaseya:unitrends_backup:*:*:*:*:*:*:*:*

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