There are values in external_references that cause problems with validating against the OASIS schemas. The schemas specify "format: uri" for the "url" attribute (schemas/common/url-regex.json), and this may enforce validation of content against RFC3986, depending on the toolset that consumes ATT&CK data.
To meet RFC3986 the square brackets should be percent-escaped as "%5B". Leading/trailing spaces should be removed, and it looks like the \u2013 and \u00a0 characters should also just be removed from the URL.
There are values in
external_references
that cause problems with validating against the OASIS schemas. The schemas specify "format: uri" for the "url" attribute (schemas/common/url-regex.json), and this may enforce validation of content against RFC3986, depending on the toolset that consumes ATT&CK data.The problematic values include:
To meet RFC3986 the square brackets should be percent-escaped as "%5B". Leading/trailing spaces should be removed, and it looks like the \u2013 and \u00a0 characters should also just be removed from the URL.