漏洞影响版本:
- ThinkPHP 5.0.5-5.0.22
- ThinkPHP 5.1.0-5.1.30
漏洞复现:
一.mac的debug环境搭建。
一键化环境搭建工具: mamp pro ,调试工具 PHPstorm
打开mamp pro，设置左上角的file->Edit Template, 设置httpd.conf (监听本地)
ServerName 127.0.0.1:8087
Listen 127.0.0.1:8087
打开mamp pro，设置左上角的file->Edit Template，设置PHP.ini 选择你的PHP版本
zend_extension="/Applications/MAMP/bin/php/php7.2.10/lib/php/extensions/no-debug-non-zts-20170718/xdebug.so" xdebug.idekey=PHPSTORM xdebug.remote_connect_back = 1 xdebug.remote_enable=on xdebug.remote_port = 9001 xdebug.remote_handler = dbgp xdebug.auto_trace = 1 xdebug.remote_log = /tmp/xdebug.log
其余的在PHPstorm上设置，设置完不行尝试加上XDEBUG_SESSION_START=xxxx ，xxxx为你debug开启的等待的key
最后，环境搭的头疼。
--------
poc: http://127.0.0.1:8087/tp5/public/index.php?s=index/\think\template\driver\file/read&cacheFile=/etc/passwd
先贴上调用栈
File.php:51, think\template\driver\File->read()
Container.php:395, ReflectionMethod->invokeArgs() //反射调用
Container.php:395, think\App->invokeReflectMethod()
Module.php:135, think\route\dispatch\Module->think\route\dispatch\{closure}()
Middleware.php:186, call_user_func_array:{/thinkphp/library/think/Middleware.php:186}()
Middleware.php:186, think\Middleware->think\{closure}()
Middleware.php:130, call_user_func:{/thinkphp/library/think/Middleware.php:130}()
Middleware.php:130, think\Middleware->dispatch()
Module.php:140, think\route\dispatch\Module->exec()
Dispatch.php:168, think\route\dispatch\Module->run()
App.php:432, think\App->think\{closure}()
Middleware.php:186, call_user_func_array:{/thinkphp/library/think/Middleware.php:186}()
Middleware.php:186, think\Middleware->think\{closure}()
Middleware.php:130, call_user_func:{/thinkphp/library/think/Middleware.php:130}()
Middleware.php:130, think\Middleware->dispatch()
App.php:435, think\App->run()
index.php:21, {main}()
最开始进入/tp5/public/index.php
<?php // +---------------------------------------------------------------------- // | ThinkPHP [ WE CAN DO IT JUST THINK ] // +---------------------------------------------------------------------- // | Copyright (c) 2006-2018 http://thinkphp.cn All rights reserved. // +---------------------------------------------------------------------- // | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 ) // +---------------------------------------------------------------------- // | Author: liu21st <[email protected]> // +---------------------------------------------------------------------- // [ 应用入口文件 ] namespace think; // 加载基础文件 require __DIR__ . '/../thinkphp/base.php'; // 支持事先使用静态方法设置Request对象和Config对象 // 执行应用并响应 Container::get('app')->run()->send();
加载基础文件，调用app应用,调用run()方法，
App.php:375, think\App->run()，在run方法中会对路由进行检测
App.php:402， $dispatch = $this->routeCheck()->init();
routeCheck()中会去执行pathinfo()方法，取$_GET['s']里面的值
public function pathinfo()
{
if (is_null($this->pathinfo)) {
if (isset($_GET[$this->config['var_pathinfo']])) {
// 判断URL里面是否有兼容模式参数
$pathinfo = $_GET[$this->config['var_pathinfo']];
unset($_GET[$this->config['var_pathinfo']]);
} elseif ($this->isCli()) {
// CLI模式下 index.php module/controller/action/params/...
$pathinfo = isset($_SERVER['argv'][1]) ? $_SERVER['argv'][1] : '';
} elseif ('cli-server' == PHP_SAPI) {
$pathinfo = strpos($this->server('REQUEST_URI'), '?') ? strstr($this->server('REQUEST_URI'), '?', true) : $this->server('REQUEST_URI');
} elseif ($this->server('PATH_INFO')) {
$pathinfo = $this->server('PATH_INFO');
}
// 分析PATHINFO信息
if (!isset($pathinfo)) {
foreach ($this->config['pathinfo_fetch'] as $type) {
if ($this->server($type)) {
$pathinfo = (0 === strpos($this->server($type), $this->server('SCRIPT_NAME'))) ?
substr($this->server($type), strlen($this->server('SCRIPT_NAME'))) : $this->server($type);
break;
}
}
}
$this->pathinfo = empty($pathinfo) || '/' == $pathinfo ? '' : ltrim($pathinfo, '/');
}
return $this->pathinfo;
}
从$_GET['s']中取参
App.php:583, think\App->routeCheck() $dispatch = $this->route->check($path, $must); // 返回一个Url对象， index|\think\template\driver\file|readreturn new UrlDispatch($this->request, $this->group, $url, [ 'auto_search' => $this->autoSearchController, ]);
在URL类中没找到含4个参数的构造函数，调用父类Dispatch的构造函数。
接着再初始化Url对象的init();方法。
第一步解析默认的URL规则。调用parseUrl($this->dispatch) ,返回URL规则
public function init()
{
// 解析默认的URL规则
$result = $this->parseUrl($this->dispatch);
return (new Module($this->request, $this->rule, $result))->init();
}
protected function parseUrl($url)
{
$depr = $this->rule->getConfig('pathinfo_depr');
$bind = $this->rule->getRouter()->getBind();
if (!empty($bind) && preg_match('/^[a-z]/is', $bind)) {
$bind = str_replace('/', $depr, $bind);
// 如果有模块/控制器绑定
$url = $bind . ('.' != substr($bind, -1) ? $depr : '') . ltrim($url, $depr);
}
list($path, $var) = $this->rule->parseUrlPath($url);
if (empty($path)) {
使用"/"进行分割，拿到 [模块/控制器/操作]
public function parseUrlPath($url)
{
....
....
} elseif (strpos($url, '/')) {
// [模块/控制器/操作]
$path = explode('/', $url);
} elseif (false !== strpos($url, '=')) {
// 参数1=值1&参数2=值2...
$path = [];
parse_str($url, $var);
} else {
$path = [$url];
}
return [$path, $var];
}
从$result = $this->parseUrl($this->dispatch); 拿到封装好的路由规则。
接着往回看return (new Module($this->request, $this->rule, $result))->init();
public function init() { // 解析默认的URL规则 $result = $this->parseUrl($this->dispatch); return (new Module($this->request, $this->rule, $result))->init(); }
在Module类中没有构造函数，在调用Dispatch父类的构造函数，在调用Module类中init()函数。将转换控制器和操作名赋值给$this,也转换控制器和操作名封装到request里面，返回当前类
public function init()
{
parent::init();
$result = $this->dispatch;
if ($this->rule->getConfig('app_multi_module')) {
// 多模块部署
$module = strip_tags(strtolower($result[0] ?: $this->rule->getConfig('default_module')));
...
...
} elseif (!in_array($module, $this->rule->getConfig('deny_module_list')) && is_dir($this->app->getAppPath() . $module)) {
$available = true;
}
...
...
// 模块初始化
if ($module && $available) {
// 初始化模块
$this->request->setModule($module);
$this->app->init($module);
} else {
throw new HttpException(404, 'module not exists:' . $module);
}
}
// 获取控制器名
$controller = strip_tags($result[1] ?: $this->rule->getConfig('default_controller'));
$this->controller = $convert ? strtolower($controller) : $controller;
// 获取操作名
$this->actionName = strip_tags($result[2] ?: $this->rule->getConfig('default_action'));
// 设置当前请求的控制器、操作
$this->request
->setController(Loader::parseName($this->controller, 1))
->setAction($this->actionName);
return $this;
}引用启明的分析：
这里存在第一个对$module的判断，需要让$available等于true，这就需要is_dir($this->app->getAppPath() . $module)成立。官方demo给出的模块是index，而实际开发程序不一定存在该模块名，
所以构造payload时这里是一个注意点。
在回到最开始的app模块
public function run(){
.....
$this->middleware->add(function (Request $request, $next) use ($dispatch, $data) {
return is_null($data) ? $dispatch->run() : $data;
});
$response = $this->middleware->dispatch($this->request);
.....
}
创建一个闭包函数，然后执行$this->middleware->dispatch($this->request);
public function dispatch(Request $request, $type = 'route')
{
return call_user_func($this->resolve($type), $request);
}
使用call_user_func回调函数，将$request作为参数传进resolve，\think\Middleware::resolve
protected function resolve($type = 'route')
{
return function (Request $request) use ($type) {
$middleware = array_shift($this->queue[$type]);
if (null === $middleware) {
throw new InvalidArgumentException('The queue was exhausted, with no response returned');
}
list($call, $param) = $middleware;
try {
//TODO此处的参数要在看一下
$response = call_user_func_array($call, [$request, $this->resolve($type), $param]);
} catch (HttpResponseException $exception) {
$response = $exception->getResponse();
}
if (!$response instanceof Response) {
throw new LogicException('The middleware must return Response instance');
}
return $response;
};
}
进入到call_user_func_array() ，继续回调，将[$request, $this->resolve($type), $param]作为参数传进去。
这里的$call参数是个闭包函数，会调用之前app模块的闭包函数。在app.php:431
#app.php:431
function (Request $request, $next) use ($dispatch, $data) { return is_null($data) ? $dispatch->run() : $data; }
Dispatch.php:168, think\route\dispatch\Module->run()
App.php:432, think\App->think\{closure}()
public function run()
{
$option = $this->rule->getOption();
// 检测路由after行为
if (!empty($option['after'])) {
$dispatch = $this->checkAfter($option['after']);
if ($dispatch instanceof Response) {
return $dispatch;
}
}
// 数据自动验证
if (isset($option['validate'])) {
$this->autoValidate($option['validate']);
}
$data = $this->exec();
return $this->autoResponse($data);
}
这时候会执行$data = $this->exec();
public function exec() { // 监听module_init $this->app['hook']->listen('module_init'); try { // 实例化控制器 $instance = $this->app->controller($this->controller, $this->rule->getConfig('url_controller_layer'), $this->rule->getConfig('controller_suffix'), $this->rule->getConfig('empty_controller')); if ($instance instanceof Controller) { $instance->registerMiddleware(); } } catch (ClassNotFoundException $e) { throw new HttpException(404, 'controller not exists:' . $e->getClass()); }
.....
return $this->app['middleware']->dispatch($this->request, 'controller');
这里有看到了熟悉的$this->app['middleware']->dispatch($this->request, 'controller');
只不过这里不再是route，而是controller，这里的controller将会再次调用exec()函数里面的闭包函数controller
$this->app['middleware']->controller(function (Request $request, $next) use ($instance) {
// 获取当前操作名
$action = $this->actionName . $this->rule->getConfig('action_suffix'); if (is_callable([$instance, $action])) {
// 执行操作方法
$call = [$instance, $action];
// 严格获取当前操作方法名
$reflect = new ReflectionMethod($instance, $action);
$methodName = $reflect->getName();
$suffix = $this->rule->getConfig('action_suffix');
$actionName = $suffix ? substr($methodName, 0, -strlen($suffix)) : $methodName;
$this->request->setAction($actionName);
// 自动获取请求变量
$vars = $this->rule->getConfig('url_param_type')
? $this->request->route()
: $this->request->param();
$vars = array_merge($vars, $this->param);
} elseif (is_callable([$instance, '_empty'])) {
// 空操作
$call = [$instance, '_empty'];
$vars = [$this->actionName];
$reflect = new ReflectionMethod($instance, '_empty');
} else {
// 操作不存在
throw new HttpException(404, 'method not exists:' . get_class($instance) . '->' . $action . '()');
}
$this->app['hook']->listen('action_begin', $call);
$data = $this->app->invokeReflectMethod($instance, $reflect, $vars);
return $this->autoResponse($data);
});
通过闭包函数controller()进行反射，跟进invokeReflectMethod
$data = $this->app->invokeReflectMethod($instance, $reflect, $vars);
public function invokeReflectMethod($instance, $reflect, $vars = [])
{
$args = $this->bindParams($reflect, $vars);return $reflect->invokeArgs($instance, $args);
}
最后就调用传入的方法和参数，进行反射。
至此，简单分析完了，学习到了使用简单闭包的方法。
官方修复方式：连接
添加如下正则，对控制器进行判断。只允许a-zA-Z.这样的字符通过
if (!preg_match('/^[A-Za-z](\w)*$/', $controller)) {
throw new HttpException(404, 'controller not exists:' . $controller);
}
参考来源：
https://paper.seebug.org/760/
https://laravel-china.org/articles/5388/closures-and-anonymous-functions-of-php-new-features
https://github.com/top-think/framework/commit/adde39c236cfeda454fe725d999d89abf67b8caf
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