20169208 2016-2017-2 《網絡攻防實踐》第十一週學習總結

20169208 2016-2017-2 《網絡攻防實踐》第十一週學習總結

SQL注入實驗

環境搭建

啓動mysql:php

sudo mysqld_safe

注意啓動後程序不會退出,能夠打開新的終端執行後續命令。
mysql

啓動Apache:sql

sudo service apache2 start

配置DNS:數據庫

sudo vim /etc/hosts

在原來的基礎上直接添加
apache

配置網站文件:vim

sudo vim /etc/apache2/conf.d/lab.conf

關閉php配置策略:緩存

sudo vim /etc/php5/apache2/php.ini

把magic_quotes_gpc=On 改成 magic_quotes_gpc = Off

服務器

lab1 select語句的sql注入

訪問:www.sqllabcollabtive.com;當咱們知道用戶而不知道到密碼的時候,咱們能夠怎麼登錄?cookie

查看登錄驗證文件:網絡

sudo vim /var/www/SQL/Collabtive/include/class.user.php

設置行號 :set number
找到其中第375行 :375

$sel1 = mysql_query ("SELECT ID, name, locale, lastlogin, gender, FROM user WHERE (name = '$user' OR email = '$user') AND pass = '$pass'");

這一句就是咱們登陸時,後臺的sql語句;咱們能夠構造一個語句,在不知道密碼的狀況下登錄;

修改完後重啓一下服務器:

sudo service apache2 restart

咱們在$user後面加上) # 這樣就會只驗證用戶名,後面的會被#註釋

繞過密碼登陸成功

lab2 update語句的sql注入

Collabtive平臺中能夠更新用戶信息,咱們要實現經過本身的用戶去修改別人的用戶信息;
咱們使用任意用戶,如: bob bob 進行登陸;

在編輯用戶的位置:user 填 ted 用戶;

Company 處填:

', `pass` = '9d4e1e23bd5b727046a9e3b4b7db57bd8d6ee684' WHERE ID = 4 # '
    注:這裏的 9d4e1e23bd5b727046a9e3b4b7db57bd8d6ee684 就是pass的md5值;

點擊修改,而後咱們退出當前用戶,使用ted用戶登陸,這個時候ted用戶的密碼應該是pass;

防護策略

SQL注入漏洞的根本問題是數據與代碼的分離失敗,所以咱們能夠針對這個緣由進行防護

防護策略1

防護轉義特殊字符使用,默認開啓magic_quotes_gpc,將magic_quotes_gpc值設爲On。

sudo vim /etc/php5/apache2/php.ini

防護策略2--避免使用特殊字符

MySQL提供一個函數 mysql_real_escape_string(),這個函數能夠用來過濾一些特殊字符;如\x00, \n, \r, , ', " and \x1a;
代碼防護示例:

sudo vim /var/www/SQL/Collabtive/include/class.user.php

修改下圖紅色框中部分

以及編輯用戶代碼部分
修改下圖紅框部分

修改成以下:

// This code was provided by the lab's author Wenliang Du, of Syracuse
    // University under the GNU Free Documentation License

    function login($user, $pass)
    {
        if (!$user)
            {
                return false;
            }

        // modification fixed
        $user = mysql_real_escape_string($user);
        $pass = mysql_real_escape_string($pass);
        $pass = sha1($pass);

        $sel1 = mysql_query("SELECT ID, name, locale, lastlogin, gender
                         FROM user WHERE (name =  '$user' OR
                         email = '$user') AND pass = '$pass'");
        $chk = mysql_fetch_array($sel1);
        if ($chk["ID"] != "")
            {
                // New user session object and cookie creation code
                // removed for brevity
                return true;
            }
        else
        {
            return false;
        }
    }

以及編輯用戶代碼:

function edit($id, $name, $realname, $email, $tel1, $tel2, $company,
              $zip, $gender, $url, $address1, $address2, $state,
              $country, $tags, $locale, $avatar = "", $rate = 0.0)
    {
    $name = mysql_real_escape_string($name);
    $realname = mysql_real_escape_string($realname);

    // modification fixed
    $company = mysql_real_escape_string($company);
    $email = mysql_real_escape_string($email);

    // further escaped parameters removed for brevity...

    $rate = (float) $rate;
    $id = (int) $id;

    if ($avatar != "")
        {
            $upd = mysql_query("UPDATE user SET name='$name', email='$email',
                                tel1='$tel1', tel2='$tel2', company='$company',
                                zip='$zip', gender='$gender', url='$url',
                                adress='$address1', adress2='$address2',
                                state='$state', country='$country',
                                tags='$tags', locale='$locale',
                                avatar='$avatar', rate='$rate' WHERE ID = $id");
        }
    else
        {
            // same query as above minus setting avatar; removed for
            // brevity
        }
    if ($upd)
        {
            $this->mylog->add($name, 'user', 2, 0);
            return true;
        }
    else
        {
            return false;
        }
    }

防護策略3--數據與sql語句的分離

經過SQL邏輯分離來告訴數據庫究竟是哪部分是數據部分,哪一部分是SQL語句部分;

提供以新的new mysqli()函數, 將這個函數寫入config/standary/config.php文件:

sudo vim /var/www/SQL/Collabtive/include/class.user.php

修改代碼以下:

// This code was provided by the lab's author Wenliang Du, of Syracuse
    // University under the GNU Free Documentation License

    function login($user, $pass)
    {
    if (!$user)
        {
            return false;
        }

    // using prepared statements

    // note that $conn is instantiated in the datenbank class found in
    // ./class.datenbank.php. this may need to be passed in, but we
    // will assume we have access to it for the sake of brevity

    $stmt = $conn->prepare("SELECT ID,name,locale,lastlogin,gender FROM user
                            WHERE (name=? OR email=?) AND pass=?");
    $stmt->bind_param("sss", $user, $user, sha1($pass));
    $stmt->execute();
    $stmt->bind_result($bind_ID, $bind_name, $bind_locale, $bind_lastlogin,
                       $bind_gender);
    $chk = $stmt->fetch();
    if ($bind_ID != "")
        {
            // New user session object and cookie creation code
            // removed for brevity
            return true;
        }
    else
        {
            return false;
        }
    }

以及編輯用戶處的代碼:

// This code was provided by the lab's author Wenliang Du, of Syracuse
    // University under the GNU Free Documentation License

    function edit($id, $name, $realname, $email, $tel1, $tel2, $company, $zip,
              $gender, $url, $address1, $address2, $state, $country, $tags,
              $locale, $avatar = "", $rate = 0.0)
    {
    // the bind_param() function wants a double, not float, though
    // they are the same internally
    $rate = (double) $rate;
    $id = (int) $id;

    if ($avatar != "")
        {
            // again, $conn is instantiated in the datenbank class, and
            // may need to be passed, but we are assuming we have
            // access to it for the sake of brevity

            // note that the app uses zip as a string, does not use
            // realname although it is passed, and the columns adress
            // and adress2 are misspelled

            $stmt = $conn->prepare("UPDATE user SET name=?, email=?, tel1=?,
                                    tel2=?, company=?, zip=?, gender=?, url=?,
                                    adress=?, adress2=?, state=?, country=?,
                                    tags=?, locale=?, avatar=? rate=?
                                    WHERE ID = ?");
            $stmt->bind_param("sssssssssssssssdi", $name, $email, $tel1, $tel2,
                               $company, $zip, $gender, $url, $address1,
                               $address2, $state, $country, $tags, $locale,
                               $avatar, $rate, $id);
            $upd = $stmt->execute();
        }
    else
        {
            $stmt = $conn->prepare("UPDATE user SET name=?, email=?, tel1=?,
                                    tel2=?, company=?, zip=?, gender=?, url=?,
                                    adress=?, adress2=?, state=?, country=?,
                                    tags=?, locale=?, rate=? WHERE ID = ?");
            $stmt->bind_param("ssssssssssssssdi", $name, $email, $tel1, $tel2,
                               $company, $zip, $gender, $url, $address1,
                               $address2, $state, $country, $tags, $locale,
                               $rate, $id);
            $upd = $stmt->execute();
        }
    if ($upd)
        {
            $this->mylog->add($name, 'user', 2, 0);
            return true;
        }
    else
        {
            return false;
        }
    }

TCP_IP網絡協議攻擊實驗

參考課程資源中的「TCP_IP網絡協議攻擊實驗.pdf 」

以SEED爲攻擊機,以Linux Metasploitable/Windows Metasploitable作靶機完成TCP/IP協議攻擊,提交本身攻擊成功截圖,加上本身的學號水印。任選兩個攻擊:
ARP緩存欺騙攻擊,ICMP重定向攻擊,SYN Flood攻擊,TCP RST攻擊,TCP 會話劫持攻擊
選擇了ARP緩存欺騙攻擊和SYN Flood攻擊

一、ARP緩存欺騙攻擊
首先查看兩個靶機的IP地址:

一個是172.16.6.21,另外一個是172.16.6.117

初始ARP緩衝中沒有內容

攻擊機能夠ping通兩個靶機

得到兩個靶機的IP和mac地址
打開攻擊機上的netwox,依次輸入五、33,使用netwox中的工具僞造ARP數據包,使用如下兩條命令

此時再查看靶機的ARP緩存,發現欺騙成功。

二、SYN Flood攻擊
查看靶機IP地址

攻擊機Telnet連接靶機23端口,成功,能夠鏈接

使用netwag攻擊進行SYN flood攻擊

打開的界面
搜索並選擇SYN

設置靶機的IP地址和端口

開啓tcpdump監聽

實施攻擊

攻擊成功,沒法Telnet連接上靶機

參考資料

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