How severe is CVE-2021-25298?

CVE-2021-25298 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-25298?

Affected package information for CVE-2021-25298 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2021-25298?

No fixed version has been published for CVE-2021-25298 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2021-25298 actively exploited in the wild?

Yes. There are 8 known exploit references for CVE-2021-25298, including 8 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-25298?

CVE-2021-25298 has an EPSS (Exploit Prediction Scoring System) score of 75.2%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2021-25298 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2021-25298 (Nagios XI OS Command Injection) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-01-18. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-02-01. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2021-25298?

CVE-2021-25298 is classified as OS Command Injection (CWE-78). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Which products and versions are affected by CVE-2021-25298?

CVE-2021-25298 affects nagios nagios xi. Check the affected-products list on this page against your deployed version to confirm exposure.

Is there exploit tooling available for CVE-2021-25298?

A Nuclei detection template exists for CVE-2021-25298, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2021-25298 published, and has it been updated?

CVE-2021-25298 was published on February 15, 2021 and was last updated on November 3, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2022-01-18 — agencies required to remediate by 2022-02-01

CVE-2021-25298

HIGH

Nagios XI version xi-5.7.5 is affected by OS command injection. The vulnerability exists in the file /usr/local/nagiosxi/html/includes/configwizards/cloud-vm/cloud-vm.inc.php due to…

Published

Feb 15, 2021

Updated

Nov 3, 2025

Affected

0 pkgs

Patched

None yet

Exploits

8 known

EPSS Exploitation Probability

via FIRST.org ↗

75.2%probability of exploitation in next 30 days

Very High Risk99th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

Nagios XI version xi-5.7.5 is affected by OS command injection. The vulnerability exists in the file /usr/local/nagiosxi/html/includes/configwizards/cloud-vm/cloud-vm.inc.php due to improper sanitization of authenticated user-controlled input by a single HTTP request, which can lead to OS command injection on the Nagios XI server.

Affected Products

1 product · 1 configurations

Application

nagios xinagios

≥ 5.5.6 && ≤ 5.7.5

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.