Обсуждение: pl/perl and security

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pl/perl and security

От
"CMVV"
Дата:
Hi,

I have discovered that in pl/perl we cannot make use of file handling.
The README file in ../pl/plperl give us an hint with an example of a
badfunc().
What are the security reasons to do so, since with postgresql extensions
(functions) written in C language we can do anything with flat files ?
Can this security issue with pl/perl be overrided ?
If so, how can i hack it ?
It will be so nice to manage files from server-based functions written in
pl/perl.
Thanx

Hugo Longo








Re: pl/perl and security

От
Jan Wieck
Дата:
CMVV wrote:
> Hi,
>
> I have discovered that in pl/perl we cannot make use of file handling.
> The README file in ../pl/plperl give us an hint with an example of a
> badfunc().
> What are the security reasons to do so, since with postgresql extensions
> (functions) written in C language we can do anything with flat files ?
> Can this security issue with pl/perl be overrided ?
> If so, how can i hack it ?
> It will be so nice to manage files from server-based functions written in
> pl/perl.
> Thanx
   The  security  issue  is  that  PL/Perl  is  designed to be a   trusted procedural language. Meaning, any
unprivileged user   can create functions in it. Having file access, which is done   under the UNIX-userid running  the
postmaster process,  any   user could modify your pg_hba.conf ...
 
   The  same  applies for PL/Tcl, why there will be an untrusted   PL/TclU in 7.1, where only DB superusers can define
functions  in it.
 
   I'm not a Perl guy, but AFAIK you can modify the command mask   used for the perl interpreter in the PL handler. But
be sure   to restrict your patched version of PL/Perl to superusers, or   accept that you created a big security hole.
 


Jan

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