CVE-2021-25297

OS Command Injection in Nagios XI version xi-5

Verified by Precogs Threat Research
Last Updated: Nov 3, 2025
Base Score
8.8HIGH

Executive Summary

CVE-2021-25297 is a high severity vulnerability affecting appsec. It is classified as OS Command Injection. This vulnerability is actively being exploited in the wild.

Precogs AI Insight

"Nagios XI contains a command injection vulnerability due to improper sanitization of user-supplied arguments. Authenticated attackers inject shell commands to execute arbitrary code on the monitoring server. Precogs API Security Engine tracks untrusted input flows to system shell execution sinks."

Exploit Probability (EPSS)
High (81.9%)
Public POC
Available
Exploit Probability
Elevated (52%)
Public POC
Actively Exploited
Affected Assets
appsecCWE-78

What is this vulnerability?

CVE-2021-25297 is categorized as a high OS Command Injection flaw with a CVSS base score of 8.8. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.

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 XI server.

This architectural defect enables adversaries to bypass intended security controls, directly manipulating the application's execution state or data layer. Immediate strategic intervention is required.

Risk Assessment

MetricValue
CVSS Base Score8.8 (HIGH)
Vector StringCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
PublishedFebruary 15, 2021
Last ModifiedNovember 3, 2025
Related CWEsCWE-78

Impact on Systems

Data Exfiltration: Attackers can extract sensitive data from backend databases, configuration files, or internal services.

Authentication Bypass: Exploiting this flaw may allow unauthorized access to protected resources and administrative interfaces.

Lateral Movement: Once initial access is gained, attackers can pivot to internal systems and escalate privileges.

How to Fix and Mitigate CVE-2021-25297

  1. Apply Vendor Patches Immediately: This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog. Apply updates per vendor instructions.
  2. Verify Patch Deployment: Confirm all instances are updated using Precogs continuous monitoring.
  3. Review Audit Logs: Investigate historical access logs for indicators of compromise related to this attack surface.
  4. Implement Defense-in-Depth: Deploy WAF rules, network segmentation, and endpoint detection to limit blast radius.

Defending with Precogs AI

Nagios XI contains a command injection vulnerability due to improper sanitization of user-supplied arguments. Authenticated attackers inject shell commands to execute arbitrary code on the monitoring server. Precogs API Security Engine tracks untrusted input flows to system shell execution sinks.

Use Precogs to continuously scan your codebase, binaries, APIs, and infrastructure for this vulnerability class and related attack patterns. Our AI-powered detection engine combines static analysis with threat intelligence to identify exploitable weaknesses before attackers do.

Start scanning with Precogs →

Vulnerability Code Signature

Attack Data Flow

StageDetail
SourceUser-supplied system argument
VectorArgument appended to a shell command string
Sinkchild_process.exec() or similar OS execution sink
ImpactRemote Code Execution (RCE), full system compromise

Vulnerable Code Pattern

// ❌ VULNERABLE: OS command injection
const { exec } = require('child_process');
function pingHost(host) {
  // Taint sink: unvalidated host string executed in shell
  exec('ping -c 4 ' + host, (error, stdout, stderr) => {
    console.log(stdout);
  });
}

Secure Code Pattern

// ✅ SECURE: ExecFile with parameter arrays
const { execFile } = require('child_process');
function pingHost(host) {
  // Sanitized execution: arguments passed safely, bypassing shell interpolation
  execFile('ping', ['-c', '4', host], (error, stdout, stderr) => {
    console.log(stdout);
  });
}

How Precogs Detects This

Precogs AI Analysis Engine natively intercepts unsafe OS command execution sinks, ensuring all arguments are properly separated from the execution context.\n

Related Vulnerabilitiesvia CWE-78

Is your system affected?

Precogs AI detects CVE-2021-25297 in compiled binaries, LLMs, and application layers — even without source code access.