Cross-site scripting (XSS) lets attackers inject client-side JavaScripts into a webpage viewed by a targeted user. To prevent malicious attacks through content manipulation, you must properly encode all user-provided content.
For example, pay close attention to how you use the Salesforce B2C Commerce Internet Store Markup Language (ISML) templates and script APIs when dealing with user-entered data.
ISML templates provide two ways to print variable values. You can use ${...}
and replace the ellipsis with the variable to be displayed or you can use the
<isprint> tag.
If you use a script expression such as ${pdict.ProductSearchResult.searchPhrase} in an ISML template, where the content type is set as follows, the script result is automatically HTML encoded.
<iscontent type="text/html" charset="UTF-8" compact="true">...</iscontent>However, if you use the same expression in an ISML template that’s included via <isinclude template=""> and no content type is
set in the included ISML snippet, B2C Commerce assumes that the content type
text/plain and no HTML encoding takes place. This is inconsistent and can
lead to XSS problems.
To correct this, you must explicitly set the content type or use <isprint value="{}"/> to ensure that you encode
the resulting HTML.
Here's an example of an insecure <isprint> tag.
<isprint
value="${pdict.ProductSearchResult.searchPhrase}"/>
Do not use HTML encoding for scenarios. The isprint tag has an encoding
attribute to encode user-entered data.
Here's a secure example of using an <isprint> tag.
<isprint value="${pdict.ProductSearchResult.searchPhrase}"
encoding="jshtml"/>
In summation, use only the appropriate encoding for its respective designed context.