Description
Unhead is a document head and template manager. Prior to 2.1.11, The link.href check in makeTagSafe (safe.ts) uses String.includes(), which is case-sensitive. Browsers treat URI schemes case-insensitively. DATA:text/css,... is the same as data:text/css,... to the browser, but 'DATA:...'.includes('data:') returns false. An attacker can inject arbitrary CSS for UI redressing or data exfiltration via CSS attribute selectors with background-image callbacks. This vulnerability is fixed in 2.1.11.
Problem types
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Product status
References
github.com/...unhead/security/advisories/GHSA-5339-hvwr-7582