CWE-830: Inclusion of Web Functionality from an Untrusted Source

How it's found

Inclusion of Web Functionality from an Untrusted Source is a specific, narrowly defined instance of a broader pattern. Testers confirm it with targeted code review and a proof-of-concept input that exercises the exact code path this weakness describes.

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 '<SCRIPT SRC="http://other.domain.here">' tags, which causes the code to run in the domain of the product, not the remote site from which the widget was loaded. As a result, the included code has access to the local DOM, including cookies and other data that the developer might not want the remote site to be able to access. Such dependencies may be desirable, or even required, but sometimes programmers are not aware that a dependency exists.

Consequences

• Execute Unauthorized Code or Commands

Where this fits in a TurboPentest engagement

This weakness is not covered by the automated black-box pentest. IntegSec pentesters cover it in a manual engagement.

Frequently asked questions

Related CWEs

• Base weakness
  CWE-829: Inclusion of Functionality from Untrusted Control Sphere