How severe is CVE-2021-40345?

CVE-2021-40345 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-40345 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 23% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-40345?

CVE-2021-40345 affects Nagios Nagios Xi. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-40345?

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

When was CVE-2021-40345 published?

CVE-2021-40345 was published on 2021-10-26 and last updated on 2026-06-17.

CVE-2021-40345

CVE-2021-40345 is a high-severity vulnerability in Nagios Nagios Xi with a CVSS 3.x base score of 7.2. Its EPSS exploit-prediction score of 23% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-77.

Key facts

Severity: High (CVSS 3.x base score 7.2)
CVSS v2: 9.0
EPSS exploit prediction: 23% (97th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-77
Affected product: Nagios Nagios Xi
Published: 2021-10-26
Last modified: 2026-06-17

Description

An issue was discovered in Nagios XI 5.8.5. In the Manage Dashlets section of the Admin panel, an administrator can upload ZIP files. A command injection (within the name of the first file in the archive) allows an attacker to execute system commands.

Frequently asked questions

What is CVE-2021-40345?: An issue was discovered in Nagios XI 5.8.5. In the Manage Dashlets section of the Admin panel, an administrator can upload ZIP files. A command injection (within the name of the first file in the archive) allows an attacker to execute system commands.
How severe is CVE-2021-40345?: CVE-2021-40345 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-40345 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 23% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-40345?: CVE-2021-40345 affects Nagios Nagios Xi. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-40345?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-40345 published?: CVE-2021-40345 was published on 2021-10-26 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nagios:nagios_xi:5.8.5:*:*:*:*:*:*:*

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