InvoicePlane permits DDL injection through tax_rate_decimal_places

InvoicePlane is a self-hosted open source application for managing invoices, clients, and payments. Prior to 1.7.2, InvoicePlane interpolates the administrator-controlled tax_rate_decimal_places setting into an ALTER TABLE statement for ip_tax_rates in Settings::index() without strict integer validation. A crafted setting value can add clauses to the schema-changing statement and remove or alter required database columns. The resulting schema corruption can permanently modify financial data structures and make the application unavailable. This vulnerability is fixed in 1.7.2.