Koha's guided report builder (reports/guided_reports.pl) reads the `order_by` CGI parameter and, for each value, a dynamically-named `{order}_ovalue` parameter, and concatenates both directly into an SQL ORDER BY clause with no allowlist or validation: `my @order_by = $input->multi_param('order_by'); foreach my $order (@order_by) { my $value = $input->param($order . "_ovalue"); $query_orderby = " ORDER BY $order $value"; }`. The resulting string is appended verbatim to the final query in C4::Reports::Guided (`$query .= $orderby;`) with no escaping. Since ORDER BY columns cannot be bound via prepared-statement placeholders, this requires an explicit allowlist, which does not exist. Any staff account with the low-privilege create_reports or execute_reports permission (commonly granted to non-admin library staff) can perform time-based blind SQL injection against the Koha database, which stores patron PII and staff/LDAP credentials.