How severe is CVE-2021-33179?

CVE-2021-33179 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-33179 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33179?

CVE-2021-33179 affects Nagios Nagios Xi. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-33179?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-33179 published?

CVE-2021-33179 was published on 2021-10-14 and last updated on 2026-06-17.

CVE-2021-33179

CVE-2021-33179 is a medium-severity vulnerability in Nagios Nagios Xi with a CVSS 3.x base score of 6.1. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 4% (90th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Nagios Nagios Xi
Published: 2021-10-14
Last modified: 2026-06-17

Description

The general user interface in Nagios XI versions prior to 5.8.4 is vulnerable to authenticated reflected cross-site scripting. An authenticated victim, who accesses a specially crafted malicious URL, would unknowingly execute the attached payload.

Frequently asked questions

What is CVE-2021-33179?: The general user interface in Nagios XI versions prior to 5.8.4 is vulnerable to authenticated reflected cross-site scripting. An authenticated victim, who accesses a specially crafted malicious URL, would unknowingly execute the attached payload.
How severe is CVE-2021-33179?: CVE-2021-33179 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-33179 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33179?: CVE-2021-33179 affects Nagios Nagios Xi. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-33179?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-33179 published?: CVE-2021-33179 was published on 2021-10-14 and last updated on 2026-06-17.

References

https://www.synopsys.com/blogs/software-security/cyrc-advisory-nagios-xi

Affected products (1)

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

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