Re: [Django] #36152: Annotation with `%` in alias fails at db level on postgres (was: Postgres backend could quote `%` in column aliases instead of failing at the db level)

[Django]

#36152: Annotation with `%` in alias fails at db level on postgres
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Reporter: Jacob Walls | Owner: (none)
Type: | Status: new
Cleanup/optimization |
Component: Database layer | Version: 5.1
(models, ORM) |
Severity: Normal | Resolution:
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
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Changes (by Jacob Walls):

* summary:
Postgres backend could quote `%` in column aliases instead of failing
at the db level
=> Annotation with `%` in alias fails at db level on postgres

Comment:

I'd be in favor of adjusting the regex. That's essentially what my code
does, and I could remove some workarounds if we get it in core.

> I wouldn't be surprised if the fact we allow % today could be exploited
one way to leak some parameter that should be present in the WHERE clause
for example.

I did try to fiddle with that before deciding whether to go to the
security team first. This had been on my medium term tinker list for a
while and finally opened an issue today because I saw a similar issue for
oracle in ticket:36147 waiting for a reproducer. (I was surprised to see
the annotation "just work" on Oracle -- this is how I noticed that backend
replaces `%` for you.)

Do we need to worry about a deprecation path for non-postgres backends?
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Ticket URL: <https://code.djangoproject.com/ticket/36152#comment:3>
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