Including third party functionality in a web-based environment is risky, especially if the source of the functionality is untrusted.
Even if the third party is a trusted source, the product may still be exposed to attacks and malicious behavior if that trusted source is compromised, or if the code is modified in transmission from the third party to the product.
This weakness is common in "mashup" development on the web, which may include source functionality from other domains. For example, Javascript-based web widgets may be inserted by using '