Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. From 2.25.0 until 2.25.2, Loofah::HTML5::Scrub.allowed_uri? does not reject javascript: URIs whose scheme is split or prefixed with the HTML5 named whitespace character references or . CGI.unescapeHTML leaves those references intact, so allowed_uri? reports the URL safe even though a browser decodes and strips the tab or line feed and executes the resulting javascript: URL. This issue affects only callers that pass HTML-encoded strings directly to allowed_uri?; Loofahs default sanitize() path is not affected. This issue is fixed in version 2.25.2.
Weakness
The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ruby-loofah | Ubuntu | upstream | * |
Potential Mitigations
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/120.html
- https://cwe.mitre.org/data/definitions/15.html
- https://cwe.mitre.org/data/definitions/182.html
- https://cwe.mitre.org/data/definitions/3.html
- https://cwe.mitre.org/data/definitions/43.html
- https://cwe.mitre.org/data/definitions/6.html
- https://cwe.mitre.org/data/definitions/71.html
- https://cwe.mitre.org/data/definitions/73.html
- https://cwe.mitre.org/data/definitions/85.html