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Comment by hrbrtglm | Hacker News Reader

Well, that's really interesting for all of us who work with multi-tenant webapp.

Maybe you took some notes.

Could you share some more info if you are free to disclose how you poked with the connection pool. I haven't look at OpenERP sources, but I think the database in use is PostgreSQL.

> "for a user of one database to access other database"

Were OpenERP using a database for each tenant or 1 database with multiple schemas ? In case it was the former case, were all databases accessed with the same credentials ? Which connection pool was it ? Pgpool / Pgbouncer ? Where was the vulnerability, code, db, pool, config setup ?

Sorry for all this questions, I'm indeed very interested and involved in this topic.

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I reported it a long time ago and it was eventually fixed a few months later. The bug report is on Launchpad but I don't know if they opened it to the public. Here is a similar issue filled on GitHub (they moved there from Launchpad and they're now called Odoo): https://github.com/odoo/odoo/issues/7243

OpenERP, at least back then, was using a single PostgreSQL cluster for a given OpenERP server. Each tenant has its own PostgreSQL database. In multiple places, OpenERP offers the administrator role of a tenant to customize OpenERP with Python code. Basically you can inject Python code for execution, and it is run in the same processes used for every tenant. OpenERP tries to limit what the Python expressions can do.

The idea of what I did was, starting from the objects I had access to, to find a way to get a database cursor to another database than mine.

The connection pool in OpenERP is custom and part of the Python code base.

To get the cursor, I poked at some object, took its class and reinstanciated (this is all straightforward to do in Python) it with the name of another database (listing other databases was another longstanding issue of OpenERP).

Thank you.

So I imagine, given their specifications, they had to give each tenant its own full PG database. I understand they have strong business logics but it does not seem very efficient. Salesforce is known to use a single oracle instance for all its tenants and I don't think their business logics is less demanding.

Giving an administrator or elevated role to the tenant connection looks like a really bad idea from the start, especially if the tenant instance is not sandboxed in a container or virtual server.

But this things are hard and a small mistake can have big consequences.

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