{"identifier":"CVE-2026-6643","cve":{"id":"CVE-2026-6643","description":"A stack-based buffer overflow vulnerability was found in the VPN Clients on the ADM. The issue stems from the use of unbounded sscanf() and passing user-controlled data directly to printf(). Due to the lack of PIE and Stack Canary protections, an authenticated remote attacker can exploit these to execute arbitrary code as the web server user. \nAffected products and versions include: from ADM 4.1.0 through ADM 4.3.3.RR42 as well as from ADM 5.0.0 through ADM 5.1.2.REO1.","published":"2026-04-20T07:16:16.543000+00:00","modified":"2026-10-26T21:10:00.170000+00:00","status":"Analyzed","score":8.6,"severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/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","cvss_version":"4.0","affected":[{"criteria":"cpe:2.3:o:asustor:data_master:*:*:*:*:*:*:*:*","versionStartIncluding":"4.1.0.rhu2","versionStartExcluding":"","versionEndIncluding":"","versionEndExcluding":"4.3.3.RR42"},{"criteria":"cpe:2.3:o:asustor:data_master:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0.0.ra82","versionStartExcluding":"","versionEndIncluding":"","versionEndExcluding":"5.1.2.reo1"}],"weaknesses":["CWE-121"],"references":[{"url":"https://www.asustor.com/security/security_advisory_detail?id=54","source":"security@asustor.com","tags":["Vendor Advisory"]}],"kev":null,"kev_checked":true,"metrics":{"cvssMetricV40":[{"source":"security@asustor.com","type":"Secondary","cvssData":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/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":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"HIGH","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","subAvailabilityImpact":"LOW","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":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","baseScore":9.9,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":3.1,"impactScore":6.0}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-04-20T13:20:51.858306Z","id":"CVE-2026-6643","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:asustor:data_master:*:*:*:*:*:*:*:*","versionStartIncluding":"4.1.0.rhu2","versionEndExcluding":"4.3.3.RR42","matchCriteriaId":"20307258-479E-4ECD-AF5E-B31019D22525"},{"vulnerable":true,"criteria":"cpe:2.3:o:asustor:data_master:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0.0.ra82","versionEndExcluding":"5.1.2.reo1","matchCriteriaId":"47B926F1-1D8F-4105-A533-45E0B4178C59"}]}]}],"source":"nvd","retrieved_at":"2026-10-28T10:19:19.168318+00:00","exploited":false,"kev_stale":false,"products":["asustor / data master"],"priority":{"label":"Assess exposure and vendor guidance","reasons":["No higher-priority signal is available in the current stored evidence."]},"epss":{"probability":0.00468,"percentile":0.40406,"date":"2026-10-28","stale":false},"version_assessment":null},"news":[],"campaigns":[],"domains":[{"domain":"www.asustor.com","source_url":"https://www.asustor.com/security/security_advisory_detail?id=54","investigate_url":"https://investigate.aeglixmind.com/#www.asustor.com"}],"arsenal_url":"https://arsenal.aeglixmind.com/?cve=CVE-2026-6643","catalog_url":"https://cves.aeglixmind.com/cve/CVE-2026-6643","research_url":"https://investigate.aeglixmind.com/research/cve/CVE-2026-6643","coverage":{"news_candidates_checked":0,"campaign_candidates_checked":0,"bounded":false,"notice":"Exact CVE mentions in stored public excerpts and reviewed campaign content only. A mention is not proof of exploitation, attribution or tool suitability. Missing matches do not establish absence."}}