Re: pl/perl and security

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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