WeKnora has Unauthorized Cross‑Tenant Knowledge Base Cloning

QFinch assessment

A cross-tenant authorization bypass in the knowledge base copy endpoint allows any authenticated user to clone (duplicate) another tenant’s knowledge base into their own tenant by knowing/guessing the source knowledge base ID. This enables bulk data exfiltration (document/FAQ content) across tenants, making the impact critical.

Potential impact

This is a Broken Access Control (BOLA/IDOR) vulnerability enabling cross-tenant data exfiltration: - Any authenticated user can trigger a clone of a victim tenant’s knowledge base into their own tenant. - Results in bulk disclosure/duplication of knowledge base contents (documents/FAQ entries/chunks), plus associated configuration.

Technical context

The POST /api/v1/knowledge-bases/copy endpoint enqueues an asynchronous KB clone task using the caller-supplied sourceid without verifying ownership (see internal/handler/knowledgebase.go). Then, the asynq task handler (ProcessKBClone) invokes the CopyKnowledgeBase service method to perform the clone operation (see internal/application/service/knowledge.go): After that, the CopyKnowledgeBase method calls the repository method to load the source knowledge base (see internal/application/service/knowledgebase.go): However, the repository method GetKnowledgeBaseByID loads knowledge bases by id only, allowing cross-tenant reads (see internal/application/repository/knowledgebase.go). The data access layer fails to enforce tenant isolation because GetKnowledgeBaseByID only filters by ID and ignores the tenantid present in the context. A secure implementation should enforce a tenant-scoped lookup (e.g., WHERE id = ? AND tenantid = ?) or use a tenant-aware repository API to prevent cross-tenant access. Service shallow-copies the KB configuration by calling GetKnowledgeBaseByID(ctx, srcKB) for the source KB, then creates a new KB under the attacker’s tenant while copying fields from the victim KB (internal/application/service/knowledgebase.go):