1if( isset( $_POST[ 'Submit' ]  ) ) {
 2    // Get input
 3    $target = $_REQUEST[ 'ip' ];
 4
 5    // 没有任何过滤
 6    // 直接运行 ping $param
 7
 8    // 可以尝试运行各种奇怪的命令组合
 9    // 输入 localhost && ls
10
11    // Determine OS and execute the ping command.
12    if( stristr( php_uname( 's' ), 'Windows NT' ) ) {
13        // Windows
14        $cmd = shell_exec( 'ping  ' . $target );
15    }
16    else {
17        // *nix
18        $cmd = shell_exec( 'ping  -c 4 ' . $target );
19    }
20
21    // Feedback for the end user
22    echo "<pre>{$cmd}</pre>";
23}

 1if( isset( $_POST[ 'Submit' ]  ) ) {
 2    // Get input
 3    $target = $_REQUEST[ 'ip' ];
 4
 5    // Set blacklist
 6    // 黑名单式过滤
 7    $substitutions = array(
 8        '&&' => '',
 9        ';'  => '',
10    );
11
12    // 然而过滤的并不严谨
13    // 使用 localHost &&& ls
14    // 或者管道?(Linux)
15    // localhost | ls`
16
17    // Remove any of the charactars in the array (blacklist).
18    $target = str_replace( array_keys( $substitutions ), $substitutions, $target );
19
20    // Determine OS and execute the ping command.
21    if( stristr( php_uname( 's' ), 'Windows NT' ) ) {
22        // Windows
23        $cmd = shell_exec( 'ping  ' . $target );
24    }
25    else {
26        // *nix
27        $cmd = shell_exec( 'ping  -c 4 ' . $target );
28    }
29
30    // Feedback for the end user
31    echo "<pre>{$cmd}</pre>";
32}

 1if( isset( $_POST[ 'Submit' ]  ) ) {
 2    // Get input
 3    $target = trim($_REQUEST[ 'ip' ]);
 4
 5    // 过滤的更猛了
 6    // Set blacklist
 7    $substitutions = array(
 8        '&'  => '',
 9        ';'  => '',
10        '| ' => '',
11        '-'  => '',
12        '$'  => '',
13        '('  => '',
14        ')'  => '',
15        '`'  => '',
16        '||' => '',
17    );
18
19    // 然而只过滤一遍
20    // localhost ||||
21
22    // Remove any of the charactars in the array (blacklist).
23    $target = str_replace( array_keys( $substitutions ), $substitutions, $target );
24
25    // Determine OS and execute the ping command.
26    if( stristr( php_uname( 's' ), 'Windows NT' ) ) {
27        // Windows
28        $cmd = shell_exec( 'ping  ' . $target );
29    }
30    else {
31        // *nix
32        $cmd = shell_exec( 'ping  -c 4 ' . $target );
33    }
34
35    // Feedback for the end user
36    echo "<pre>{$cmd}</pre>";
37}