Risk of cross-site scripting attacks w/Stylesheet enabled, what about Aptivista CSS macro?

[John Corwith]

So the following Confluence doc mentions the XSS risk, does the Adaptavista CSS Stylesheet macro pose the same security risk?

https://confluence.atlassian.com/doc/styling-confluence-with-css-166528400.html

https://www.adaptavist.com/doco/display/CFP/Style+Sheet

[Shannon S · Accepted solution]

Hello John.

Thank you for contacting us about this!

According to Content Formatting documentation from Adaptavist:

As Confluence is a content-management system that allows user-generated content to be posted on the web, precautions have been taken within the Content Formatting Add-On to prevent cross-site scripting attacks:

The Content Formatting html macros specifically prevent the use of unknown HTML attributes, and all parameter values are checked against an allowable range to ensure that they are not being abused.

For example, where an html attribute has an 'enum' set of values, ONLY those values are allowed; where it's a free text attribute, the value is checked for breaking out of the attribute rules. If any 'bad' values are found a macro exception is thrown and the output is not rendered.

Additional Precautions:

• All of the 'form' html elements are disabled by default and must be manually enabled by an administrator.

• JavaScript attributes are not allowed and cannot be enabled e.g. 'onclick'.

I hope that clarifies things for you, but I've included your question in the Adaptavist collection as well, in case anyone from Adaptavist has any further information for you regarding this.

Regards,

Shannon