The open source PHP forum software myBB recently published a new update, version 1.8.21. This is a security release fixing a Stored XSS vulnerability in the private messaging and post modules.

What Are the Risks?

Unpatched websites could allow bad actors to send booby-trapped posts or private messages to users. These would execute rogue JavaScript code when opened, momentarily giving the attacker’s scripts all privileges to the targeted account.

If administrators are targeted, successful attacks could trick their browser into hacking their own site by executing code on the server and grant full power over the site to the assailants.

Continue reading Stored XSS in MyBB <= 1.8.20 at Sucuri Blog.

Via Sucuri.net