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Vulnerability record · CVE-2021-37344 · published 13 August 2021

CVE-2021-37344: Nagios XI Switch Wizard OS command injection allows remote code execution

Nagios · Nagios Xi Switch Wizard

Nagios XI Switch Wizard before version 2.5.7 fails to neutralise special elements used in an OS command, allowing OS command injection. Because the flaw is network reachable with no privileges or user interaction required, it can lead to remote code execution on the Nagios XI host.

9.8 CVSS 3.1 Critical EPSS 97% · top 0.1% CWE-78 · OS command injection
9.8CVSS 3.1 base score, v2 7.5
97%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

Nagios XI Switch Wizard before version 2.5.7 is vulnerable to remote code execution through improper neutralisation of special elements used in an OS Command (OS Command injection).

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 18 September 2026. Confidence: medium.

critical priorityCVSS 9.8 with network reachability, no authentication or interaction, and very high EPSS make this a top remediation priority despite no KEV listing.

What it is

Nagios XI Switch Wizard before version 2.5.7 fails to neutralise special elements used in an OS command, allowing OS command injection. Because the flaw is network reachable with no privileges or user interaction required, it can lead to remote code execution on the Nagios XI host.

Impact

An unauthenticated network attacker can execute arbitrary OS commands on the Nagios XI server, compromising the monitoring host and potentially the systems it manages.

Attack surface

Reached over the network via the Switch Wizard component; the CVSS vector (AV:N/PR:N/UI:N) indicates no authentication and no user interaction are required.

Exploitation

Not listed in CISA KEV and no public exploit references are provided, but EPSS is very high at 0.968 (99.9th percentile), indicating strong predicted exploitation activity.

What to do

  • Upgrade Nagios XI Switch Wizard to version 2.5.7 or later, per the vendor change log.
  • If immediate upgrade is not possible, restrict network access to the Nagios XI web interface to trusted management networks.
  • Review and harden the Nagios XI service account so injected commands run with minimal privileges.
  • Monitor the vendor change log and advisories for further updates on this component.

Detection

  • Inspect Nagios XI web and application logs for Switch Wizard requests containing shell metacharacters or unexpected command strings.
  • Monitor for child processes spawned by the Nagios XI web server or PHP process, especially shells and system utilities.
  • Alert on outbound network connections originating from the Nagios XI host to unexpected destinations.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://www.nagios.com/downloads/nagios-xi/change-log/ Release NotesVendor Advisory
https://www.nagios.com/downloads/nagios-xi/change-log/ Release NotesVendor Advisory

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Source: NIST National Vulnerability Database (record CVE-2021-37344), CISA KEV, FIRST EPSS (scores of 2026-09-22). This page is refreshed as NVD updates the record.