CVE-2026-72609

The vulnerability in Koha's GetInvoices function reveals a specific pattern failure: developers implemented an allow-list for column names in the ORDER BY clause but concatenated the direction token ('ASC'/'DESC') without validation. This is the latest iteration of a documented regression in SQL injection defense — each generation of secure coding guidance produces a new mutation where developers secure the obviously dangerous input while missing the adjacent syntax token. The direction token was considered 'safe' because it supposedly accepts only two values, but that assumption has been exploited before in other codebases. Standard parameterized queries cannot bind ASC/DESC tokens since they are syntactic tokens, not values — this creates a genuine technical constraint that pushes developers toward concatenation, but the fix requires recognizing that direction tokens are an entire class of injection surface, not just this specific instance. The permission requirement (acquisition => order_receive) limits the initial attacker pool, but in library deployments, acquisitions staff often have cross-module access to cataloging and patron management. More critically, the extraction target isn't module data — it's bcrypt password hashes and TOTP secrets stored in the system, making this a credential-harvesting operation rather than opportunistic data theft. The time-based blind extraction is slow but viable for persistent attackers. Check your entire codebase for other ORDER BY constructions where column names are validated but adjacent tokens are concatenated — this pattern has appeared repeatedly and likely exists elsewhere in Koha's legacy C4 modules. The allow-list approach itself creates maintenance debt: every new schema column requires updating the allow-list, guaranteeing ongoing attention to this query construction path.

Reviewed through automated stages and approved by a human before publication.