SmartFoxServer 2X 2.17.0 God Mode Console WebSocket XSS  
Vendor: gotoAndPlay()  
Product web page:  
Affected version: Server: 2.17.0  
Remote Admin: 3.2.6  
SmartFoxServer 2X, Pro, Basic  
Summary: SmartFoxServer (SFS) is a comprehensive SDK for  
rapidly developing multiplayer games and applications  
with Adobe Flash/Flex/Air, Unity, HTML5, iOS, Universal  
Windows Platform, Android, Java, C++ and more. SmartFoxServer  
comes with a rich set of features, an impressive  
documentation set, tens of examples with their source,  
powerful administration tools and a very active support  
forum. Born in 2004, and evolving continuously since  
then, today SmartFoxServer is the leading middleware to  
create large scale multiplayer games, MMOs and virtual  
communities. Thanks to its simplicity of use, versatility  
and performance, it currently powers hundreds of projects  
all over the world, from small chats and turn-based games  
to massive virtual worlds and realtime games.  
Desc: Authenticated Cross-Site Scripting was discovered.  
Input passed to the AdminTool console is not properly  
sanitized before being returned to the user. This can be  
exploited to execute arbitrary HTML code in a user's browser  
session in context of an affected site.  
private String checkHTML(String data) {  
if (data.indexOf(60) > -1 && data.indexOf("<span") == -1) {  
data = data.replaceAll("\\<", "<");  
return data.replaceAll("\\>", ">");  
return data;  
Tested on: Windows (all) 64bit installer  
Linux/Unix 64bit installer  
MacOS (10.8+) 64bit installer  
Java 1.8.0_281  
Python 3.9.1  
Python 2.7.14  
Vulnerability discovered by Gjoko 'LiquidWorm' Krstic  
Advisory ID: ZSL-2021-5626  
Advisory URL:  
CVE ID: CVE-2021-26549  
Typing payload:  
WebSocket payload: