Microweber, an open-source website builder and content management system, has a stored cross-site scripting (XSS) vulnerability, according to security researchers. 

The security flaw, identified as CVE-2022-0930 by researchers James Yeung and Bozhidar Slaveykov, was patched in Microweber version 1.2.12. The issue developed as a result of flaws in older versions of Microweber's content filtering protections. 

Because of these flaws, attackers could upload an XSS payload as long as it contained a file ending in 'html' — a category that encompasses far more than simply plain.html files. Once this payload is uploaded, a URL with malicious HTML can be viewed and malicious JavaScript performed. 

An attacker could steal cookies before impersonating a victim, potentially the administrator of a compromised system, by controlling a script that runs in the victim's browser. A technical blog article by Yeung and Slaveykov, which includes a proof-of-concept exploit, gives additional detail about the assault. Microweber was asked to comment on the researchers' findings via a message sent through a webform on The Daily Swig's website. Microweber responded by confirming that the "issue is already fixed." 

When asked how they found Microweber as a target, Yeung told The Daily Swig, “I came across huntr.dev and found other researchers had found vulnerabilities on Microweber and that's why I joined that mania!” 

The vulnerabilities discovered in Microweber are similar to those found in other comparable enterprise software packages. The researcher explained, “I have found similar vulnerabilities in multiple CMS like Microweber, and I found that most of them are lacking user input sanitization from HTTP requests (some of which are not intended to be submitted from client).” 

To avoid issues in this area, Yeung determined that developers should gradually shift toward allow-lists and away from utilising block-lists.