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PatchSiren cyber security CVE debrief

CVE-2021-25298 Nagios CVE debrief

CVE-2021-25298 affects Nagios XI and is identified by CISA as a known exploited vulnerability. The official guidance in the supplied corpus is to apply updates per vendor instructions, making this a high-priority defensive item for any environment running Nagios XI.

Vendor
Nagios
Product
Nagios XI
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2022-01-18
Original CVE updated
2022-01-18
Advisory published
2022-01-18
Advisory updated
2022-01-18

Who should care

Administrators, security teams, and incident responders responsible for Nagios XI deployments should prioritize this CVE, especially because it is listed in CISA’s Known Exploited Vulnerabilities catalog.

Technical summary

The supplied official sources describe CVE-2021-25298 as an OS command injection issue in Nagios XI. CISA has marked it as known exploited, and the KEV entry directs defenders to apply updates per vendor instructions. The supplied corpus does not include deeper technical details, proof-of-concept information, or affected version ranges.

Defensive priority

High. CISA’s KEV inclusion indicates confirmed exploitation risk, so remediation should be treated as urgent and tracked to completion.

Recommended defensive actions

  • Identify all Nagios XI instances in your environment and confirm which are exposed or externally reachable.
  • Apply the vendor-recommended update or mitigation path referenced by Nagios and CISA as soon as possible.
  • Prioritize remediation before the KEV due date of 2022-02-01 for any unpatched instance still in service.
  • Verify post-update status and monitor for signs of command-injection abuse or unexpected administrative activity.
  • If immediate patching is not possible, place compensating controls around access to the Nagios XI interface and document the exception.

Evidence notes

This debrief is based only on the supplied official records: the CVE record, NVD detail page, and CISA KEV catalog entry. The corpus explicitly identifies the issue as Nagios XI OS command injection and marks it as known exploited. No CVSS score, affected-version list, exploit details, or remediation specifics beyond "apply updates per vendor instructions" were provided in the source corpus.

Official resources

The CVE and source item were published and modified on 2022-01-18 in the supplied timeline. CISA KEV metadata shows dateAdded 2022-01-18 and dueDate 2022-02-01. This debrief does not use generation or review time as the vulnerability date.