xss bypass the sanitize in pbboard/pbboard-3.0.4
Feb 2nd 2023
hi,@maintainer.The filter you use to clean xss is unsafe.Please choose an xss filter with a large number of users and a high evaluation
Proof of Concept
1.Login to the forum as any user.
2.Send dangerous messages to admin users.
3.The value of the Message is below
<a/href="1"/ononclickclick="alalertert`you are hacked`">click me</a>
4.Admin users view the Message sent by the attacker.Click the link the attacker sent.
(1) To steal the administrator account or cookie, the intruder can log in to the background as an administrator. It enables intruders to manipulate background data maliciously, including reading, changing, adding and deleting some information.
(2) Stealing users' personal information or login accounts will pose a huge threat to the user security of the website. For example, pretend to be a user for various operations.
(3) The website hangs horses. First, embed the malicious attack code into the Web application. When the user browses the hanging horse page, the user's computer will be implanted with a Trojan horse.
(4) Send advertisements or spam messages. Attackers can use XSS vulnerabilities to plant advertisements or send spam, seriously affecting