MyBB 1.8.17 - Cross-Site Scripting

2018-09-1200:00:00

0xB9

6.1 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

CHANGED

Confidentiality Impact

LOW

Integrity Impact

LOW

Availability Impact

NONE

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

4.3 Medium

CVSS2

Access Vector

NETWORK

Access Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

NONE

Integrity Impact

PARTIAL

Availability Impact

NONE

AV:N/AC:M/Au:N/C:N/I:P/A:N

0.015 Low

EPSS

Percentile

86.9%

JSON

MyBB 1.8.17 - Cross-Site Scripting

# Exploit Title: MyBB 1.8.17 - Cross-Site Scripting
# Date: 2018-08-11
# Author: 0xB9
# Twitter: @0xB9Sec
# Contact: 0xB9[at]pm.me
# Software Link: https://mybb.com/download/
# Version: 1.8.17
# Tested on: Ubuntu 18.04
# CVE: CVE-2018-15596

# 1. Description:
# On the forum RSS Syndication page you can generate a URL for example... 
# http://localhost/syndication.php?fid=&type=atom1.0&limit=15, the thread titles on 
# those generated links aren't sanitized. 
 
# 2. Proof of Concept:

- Make or find a thread of yours on the RSS feed
- Use this payload as the thread title  <a href="//google.com">Cool Thread Title</a>
- View RSS feed with your thread again but with the generated URL and click on your thread
- When the thread is clicked you will be redirected to google.com