Re: lastval exposes information that currval does not - Mailing list pgsql-hackers

From Andrew Dunstan
Subject Re: lastval exposes information that currval does not
Date
Msg-id 44C929B1.8060306@dunslane.net
Whole thread Raw
In response to Re: lastval exposes information that currval does not  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: lastval exposes information that currval does not  (Phil Frost <indigo@bitglue.com>)
List pgsql-hackers
Tom Lane wrote:

>Alvaro Herrera <alvherre@commandprompt.com> writes:
>  
>
>>What we should really do is have lastval() fail if the user does not
>>have appropiate permissions on the schema.  Having it not fail is a bug,
>>and documenting a bug turns it not into a feature, but into a "gotcha".
>>    
>>
>
>I'm unconvinced that it's either a bug or a gotcha.  lastval doesn't
>tell you which sequence it's giving you a value from, so I don't really
>see the reasoning for claiming that there's a security hole.  Also,
>*at the time you did the nextval* you did have permissions.  Does anyone
>really think that a bad guy can't just remember the value he got?
>lastval is merely a convenience.
>
>
>  
>

Is that true even if it was called by a security definer function?

I too don't think that the security danger of knowing the value of a 
(possibly unknown) sequence is very high, but that's another argument.

cheers

andrew



pgsql-hackers by date:

Previous
From: Andrew Dunstan
Date:
Subject: Re: [COMMITTERS] pgsql: another try at keeping AIX/ppc
Next
From: Tom Lane
Date:
Subject: Re: Warnings in pgstattuple