Re: [SQL] security: escaping user-supplied data - Mailing list pgsql-sql

From Herouth Maoz
Subject Re: [SQL] security: escaping user-supplied data
Date
Msg-id l03130300b428b43b893a@[147.233.159.109]
Whole thread Raw
In response to security: escaping user-supplied data  (Jason Uhlenkott <jpu31@uhlenkott.net>)
Responses Re: [SQL] security: escaping user-supplied data  ("Albert REINER" <areiner@tph.tuwien.ac.at>)
Re: [SQL] security: escaping user-supplied data  ("tjk@tksoft.com" <tjk@tksoft.com>)
List pgsql-sql
At 02:31 +0200 on 12/10/1999, Jason Uhlenkott wrote:


> The statements I generate are usually of the form:
> INSERT INTO foo (bar, bas) VALUES ('abc', 'def');
> but the 'abc' and 'def' come from an untrusted source, so if they supply
> a string like "def'); delete from foo; '" they can make me do this:
> INSERT INTO foo (bar, bas) VALUES ('abc', 'def'); delete from foo; '');
>
> What do I need to do to prevent this?  My current plan is to prepend a
> backslash to every single-quote, backslash, and semicolon in the
> untrusted string.  Are there any other special characters I should watch
> out for?  Is it possible to do something evil despite your special
> characters being prepended with a backslash?

I don't see why you would want to escape a semicolon. If you escape single
quotes and backslashes, the above situation won't happen - the string won't
be finished until the first unescaped quote - yours - is encountered.
Semicolons are not special in strings.

Herouth

--
Herouth Maoz, Internet developer.
Open University of Israel - Telem project
http://telem.openu.ac.il/~herutma




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