This SAP Note describes how to reduce the risk of possible cross-site scripting (XSS) attacks in JSF.

There are two precautions already in place at SAP for XSS prevention in JSF applications, namely the ICM filter mechanism and the SAP component library for JSF.
o ICM filter mechanism
The ICM filter mechanism already provides some protection: by means of a configurable standard pattern filter, the ICM content filter can be configured to block code injection input as for example <script><java script code></script> or javascript:<java script code>
However, the ICM filter mechanism only provides protection in the special case where <script> and javascript keywords are written into the input field directly.
o SAP component library for JSF
The SAP component library for JSF (a. k. a. Light Speed Faces library, LSF) already has built-in support to protect against XSS: By means of the Unified Rendering in LS, the LSF library offers “escaped” (i. e. output encoded), and thus secure counterparts of the writeAttribute methods in Sun’s reference implementation.