FlatPress Cross-Site Scripting (XSS) Scanner

FlatPress is a lightweight content management system (CMS) used for blogging. It is favored by individuals and small businesses due to its simplicity and ease of setup. FlatPress is particularly attractive to those looking for a PHP/MySQL-free experience, as it does not rely on a database but instead uses text files for data storage. The software is developed and maintained by a community-driven team, providing users with a customizable platform that allows theme modifications and plugin expansions. Despite its lighter infrastructure, FlatPress is designed to deliver comprehensive blogging capabilities comparable to more complex systems. Used globally, it serves as an effective tool for those seeking an accessible platform for web presence creation.

The Cross-Site Scripting (XSS) vulnerability in FlatPress allows attackers to execute arbitrary JavaScript code in a victim's browser. XSS vulnerabilities can be exploited by injecting malicious scripts into web pages viewed by other users. The primary threat posed by XSS attacks is the unauthorized control of user sessions, which can lead to identity theft or the hijacking of a legitimate user's session. XSS may also result in the spread of web worms and access to sensitive information. As such, they represent a significant threat, especially in platforms allowing for user-generated content or comments. The XSS vulnerability in FlatPress is stored, meaning the malicious script can persist on the site and affect multiple users.

The technical aspect of this XSS vulnerability involves the "page" parameter, which is exploited to inject scripts that trick the browser into executing unauthorized code. The endpoint concerned with this vulnerability is associated with managing static pages, a critical component for displaying content in FlatPress. When a payload is injected into the “page” parameter, it can store the malicious script in a way that executes whenever a page is viewed. Such exploitation is especially dangerous if part of an admin or similarly sensitive area of the application. Attackers typically craft URLs with these scripts embedded, relying on users to inadvertently execute these scripts.

If exploited, this XSS vulnerability can lead to a range of serious consequences. A compromised site could be used to steal session tokens, allowing attackers unauthorized access to user accounts, including those with administrative privileges. Compromised scripts could be used to redirect users to malicious sites or load further malware. Beyond user impact, a successful XSS attack could damage the site's reputation, leading to distrust and reduced user engagement. The exploitation of such vulnerability could also facilitate further attacks on connected systems within an organization’s network.

REFERENCES

• https://github.com/flatpressblog/flatpress/issues/153