Cyber Resilience

CVE-2021-25297

RCE in Nagios Xi 5.5.6 – 5.7.5

CISA KEVActive ExploitationEUVD ExploitedPublic PoCRCECommand Injection
Published
15 February 2021
Modified
09 July 2026
KEV Added
18 January 2022
Patch / advisory
View advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.56 99th percentile
Risk Priority 90 floored blend · peak EPSS

Summary

CVE-2021-25297 is a high-severity OS Command Injection (CWE-78) vulnerability in Nagios Nagios Xi. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

Nagios XI version xi-5.7.5 contains an OS command injection vulnerability in the file /usr/local/nagiosxi/html/includes/configwizards/switch/switch.inc.php. The flaw stems from insufficient sanitization of user-controlled input supplied over a single HTTP request and is tracked under CWE-78 with a CVSS 3.1 score of 8.8.

An authenticated attacker with network access can submit a crafted request to the affected component and execute arbitrary operating-system commands on the Nagios XI server, resulting in full confidentiality, integrity, and availability impact without user interaction.

Public exploit code has been posted to Packet Storm and a detailed bug report is available on GitHub; the Nagios versions page and vendor site provide the authoritative locations for subsequent software updates.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

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/switch/switch.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…

more

XI server.

CWE(s)
NVD-CWE-OtherCWE-78
KEV Date Added
18 January 2022

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
attack.mitre.org →
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
attack.mitre.org →
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
attack.mitre.org →
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2019-15949Same product: Nagios Nagios Xiboth on KEV
CVE-2021-25298Same product: Nagios Nagios Xiboth on KEV
CVE-2025-34134Same product: Nagios Nagios Xi
CVE-2024-14005Same product: Nagios Nagios Xi
CVE-2026-2042Same product: Nagios Nagios Xi
CVE-2025-34227Same product: Nagios Nagios Xi
CVE-2018-8735Same product: Nagios Nagios Xi
CVE-2024-14003Same product: Nagios Nagios Xi
CVE-2024-14008Same product: Nagios Nagios Xi
CVE-2025-34286Same product: Nagios Nagios Xi

Affected Assets

nagios
nagios xi
5.5.6 — 5.7.5

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.5
  • V1.2.8
  • V15.2.5

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-27 Platform-independent Applications
addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

SI-10 Information Input Validation
addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.

PR.PS-02 partial match
prevents

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.

References