Opened 8 years ago

Closed 8 years ago

#10160 closed (fixed)

F expression literals should use bind parameters

Reported by: Ian Kelly Owned by: nobody
Component: Database layer (models, ORM) Version: master
Severity: Keywords:
Cc: Triage Stage: Unreviewed
Has patch: yes Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: UI/UX:

Description

To prevent SQL injection attacks, Python values used within F() expressions should be processed as bind parameters rather than be inserted directly into the SQL.

Attachments (2)

10160.diff (1.3 KB) - added by Ian Kelly 8 years ago.
10160-2.diff (1.4 KB) - added by Ian Kelly 8 years ago.

Download all attachments as: .zip

Change History (6)

Changed 8 years ago by Ian Kelly

Attachment: 10160.diff added

comment:1 Changed 8 years ago by Ian Kelly

Has patch: set

Changed 8 years ago by Ian Kelly

Attachment: 10160-2.diff added

comment:2 Changed 8 years ago by Ian Kelly

The first patch doesn't quite work. It successfully passes non-string types as bind parameters, but string values were still just getting processed by quote_name, and string values are the most dangerous.

The new patch fixes this by removing the attempt to process the value with quote_name entirely. This introduces a minor backward incompatibility, since it's no longer possible to do things like .filter(amount__lt=F('max_amount')-'surplus') and have 'surplus' automatically be included as a field name. But this can still be accomplished by using F('surplus') instead, which is better anyway since it's explicit.

comment:3 Changed 8 years ago by Alex Gaynor

Yeah that's defintely an improvement F('field') - 'string' shouldn't turn 'string' into a fieldname automatically.

comment:4 Changed 8 years ago by Russell Keith-Magee

Resolution: fixed
Status: newclosed

(In [9820]) Fixed #10160 -- Modified evaluation of F() expressions to protect against potential SQL injection attacks. Thanks to Ian Kelly for the suggestion and patch.

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