The Angular SSR is a server-rise rendering tool for Angular applications. Versions prior to 21.2.0-rc.1, 21.1.5, 20.3.17, and 19.2.21 have a Server-Side Request Forgery (SSRF) vulnerability in the Angular SSR request handling pipeline. The vulnerability exists because Angular’s internal URL reconstruction logic directly trusts and consumes user-controlled HTTP headers specifically the Host and `X-Forwarded-*` family to determine the application's base origin without any validation of the destination domain. Specifically, the framework didn't have checks for the host domain, path and character sanitization, and port validation. This vulnerability manifests in two primary ways: implicit relative URL resolution and explicit manual construction. When successfully exploited, this vulnerability allows for arbitrary internal request steering. This can lead to credential exfiltration, internal network probing, and a confidentiality breach. In order to be vulnerable, the victim application must use Angular SSR (Server-Side Rendering), the application must perform `HttpClient` requests using relative URLs OR manually construct URLs using the unvalidated `Host` / `X-Forwarded-*` headers using the `REQUEST` object, the application server must be reachable by an attacker who can influence these headers without strict validation from a front-facing proxy, and the infrastructure (Cloud, CDN, or Load Balancer) must not sanitize or validate incoming headers. Versions 21.2.0-rc.1, 21.1.5, 20.…

Affected: npm: @angular/ssr, npm: @nguniversal/common, npm: @nguniversal/express-engine

A [Server-Side Request Forgery (SSRF)](https://developer.mozilla.org/en-US/docs/Web/Security/Attacks/SSRF) vulnerability has been identified in the Angular SSR request handling pipeline. The vulnerability exists because Angular’s internal URL reconstruction logic directly trusts and consumes user-controlled HTTP headers specifically the Host and `X-Forwarded-*` family to determine the application's base origin without any validation of the destination domain.

Specifically, the framework didn't have checks for the following: - **Host Domain**: The `Host` and `X-Forwarded-Host` headers were not checked to belong to a trusted origin. This allows an attacker to redefine the "base" of the application to an arbitrary external domain. - **Path & Character Sanitization**: The `X-Forwarded-Host` header was not checked for path segments or special characters, allowing manipulation of the base path for all resolved relative URLs. - **Port Validation**: The `X-Forwarded-Port` header was not verified as numeric, leading to malformed URI construction or injection attacks.

This vulnerability manifests in two primary ways:

- **Implicit Relative URL Resolution**: Angular's `HttpClient` resolves relative URLs against this unvalidated and potentially malformed base origin. An attacker can "steer" these requests to an external server or internal service. - **Explicit Manual Construction**: Developers injecting the `REQUEST` object to manually construct URLs (for fetch or third-party SDKs) d…

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Angular ausnutzen, um falsche Informationen darzustellen, Daten zu manipulieren und Cross-Site-Scripting-Angriffe durchzuführen.