Introduction
During some happy hunting, I found two XSS vulnerabilities in the FooGallery WordPress plugin (version 2.4.14), which made 50k instances vulnerable on the day of discovery! These can allow attackers to execute malicious code and gain unauthorized access to administrative functionalities. Below is a detailed explanation of these vulnerabilities and how they can be exploited.
Vulnerability 1: Stored XSS via Custom URL Field
The first vulnerability allows a user with Contributor permissions to modify an album with a gallery and set a “custom URL” containing malicious XSS code. For example, by entering:
When an administrator accesses the edit page of the same element, the malicious code executes, displaying an alert with the JavaScript value 8. This type of Stored Cross-Site Scripting can be used to execute actions in the context of an administrator, potentially leading to further exploitation.
Proof of Concept
Here is an example HTTP request that demonstrates how a Contributor can save a custom URL with malicious code:
The custom_url field is affected and allows the injection of malicious code.
Vulnerability 2: Stored XSS via Image Metadata
The second vulnerability affects users with permissions to edit gallery content (Author+). These users can modify the name of a single image by clicking on the “i” icon on the image. The modified content can include any JavaScript or HTML code, which is then displayed to other users editing the same image or accessing the gallery. If the WordPress admin dashboard panel displays a list of recent actions, it will also execute the injected code.
Proof of Concept
Here is an example HTTP request that demonstrates how an Author can inject malicious code into an image’s metadata:
The:
- foogallery%5Btitle%5D
- foogallery%5Balt-text%5D
- foogallery%5Bcustom-url%5D
- foogallery%5Bcustom-class%5D
fields are affected and allow the injection of malicious code:
Conclusion
These vulnerabilities in the FooGallery WordPress plugin can lead to security issues, including unauthorized administrative access and further exploitation of the system. It is crucial to update to the latest version of the plugin.
By understanding these vulnerabilities and their potential impact, users can take proactive steps to secure their websites and protect against malicious activities.
References
