Angular: SSRF and Cross-Origin Credential Disclosure via URL Resolution Discrepancy in SSR

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 20.3.30, 21.2.22, and 22.1.4, Angular Server-Side Rendering in @angular/platform-server processes user-controlled resource or request URLs through HttpClient after application code validates them with WHATWG URL parsing. The resolveUrl and parseUrl utilities called String.prototype.trim(), which removed leading Unicode whitespace such as U+00A0 or U+FEFF after the input passed a same-origin check, converting a relative path into a protocol-relative attacker-controlled URL. In affected applications that attach sensitive server-side credentials such as Authorization headers to approved requests, relativeUrlsTransformerInterceptorFn then dispatched the request to the attacker-controlled origin, causing SSRF and credential disclosure. This issue is fixed in versions 20.3.30, 21.2.22, and 22.1.4.