CVE-2019-15949

What is this vulnerability?

CVE-2019-15949 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 before 5.6.6 allows remote command execution as root. The exploit requires access to the server as the nagios user, or access as the admin user via the web interface. The getprofile.sh script, invoked by downloading a system profile (profile.php?cmd=download), is executed as root via a passwordless sudo entry; the script executes check_plugin, which is owned by the nagios user. A user logged into Nagios XI with permissions to modify plugins, or the nagios user on the server, can modify the check_plugin executable and insert malicious commands to execute as root.

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

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-2019-15949

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 insufficient sanitization of input passed to the getprofile.sh script. Authenticated attackers inject malicious parameters to execute arbitrary OS commands as root. 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.

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Vulnerability Code Signature

Attack Data Flow

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