子域名接管防护（DNS/存储桶/权限）最佳实践

背景与价值子域名接管常源于DNS指向未占用资源或权限配置错误。统一检测与治理可阻断风险。统一规范DNS治理：定期扫描CNAME/A记录指向的资源是否已绑定并受控。存储桶绑定：启用强绑定与私有权限，拒绝匿名与跨账户绑定。审计通道：记录异常指向与接管尝试。核心实现DNS与资源占用校验（示意）type Record = { name: string; type: 'A'|'CNAME'; target: string } type Resource = { host: string; claimed: boolean } function occupied(r: Record, resources: Resource[]): boolean { const host = r.type === 'CNAME' ? r.target : r.name const found = resources.find(x => x.host.toLowerCase() === host.toLowerCase()) return !!found && found.claimed } function audit(records: Record[], resources: Resource[]): { risks: Record[] } { const risks: Record[] = [] for (const r of records) if (!occupied(r, resources)) risks.push(r) return { risks } } 落地建议对指向云存储/静态托管的CNAME进行占用校验与强绑定，避免未占用导致接管。禁用匿名读取与跨账户绑定，启用受控账户与权限策略。验证清单是否存在未占用的DNS指向；存储桶是否强绑定与权限收敛。