Re: Why are people so afraid of underscore parameters ?

In article <b3cb12d6.0208301335.369c8e18_at_posting.google.com>, yong321_at_yahoo.com says...
>
>kazimiej_at_bms.com (Joe Kazimierczyk) wrote in message
>news:<e2242da1.0208290958.2dd481ec_at_posting.google.com>...
>> Even worse: with alter session and readable trace files,
>> in Oracle 7, 8i, and up, it's possible to find user's passwords
>> in plain text. This clever trick can be found in the white paper
>> "exploiting and protecting oracle" at www.pentest-limited.com
>>
>> All the more reason to be cautious when using undocumented features.
>
>Hi, Joe,
>
>I think you're referring to
>http://www.pentest-limited.com/utl_file.htm. Now I know what event Tom
>Kyte was talking about. I tested it. Even library cache dump at level
>3, "alter user..identified by.." is shown, although v$sql only shows
>the first 20 characters such as "alter user yong iden". So if a user
>can alter session and see trace, the only workaround is for the DBA to
>flush shared pool right after changing a user's password. I wish some
>events had to be set with a command other than alter session. Allowing
>alter session to dump library cache is like allowing setenv or stty
>commands to run crash(1M) in Solaris (crash is used to "examine system
>image").
>
>Yong Huang

stored procedures give you this level of granularity.

suppose you wanted people to be able to set query_rewrite_enabled but not dump the library cache.

Ok, then

create procedure set_query_rewrite_enabled( p_string in varchar2 ) as
begin

   execute immediate 'alter session set query_rewrite_enabled = ' || p_string; end;
/

as a priveleged user and grant execute on that to whomever. Now, you have the level of granularity you desire (and then some)

--
Thomas Kyte (tkyte@oracle.com)             http://asktom.oracle.com/ 
Expert one on one Oracle, programming techniques and solutions for Oracle.
http://www.amazon.com/exec/obidos/ASIN/1861004826/  
Opinions are mine and do not necessarily reflect those of Oracle Corp