The Angular Language Service VS Code Extension provides a rich editing experience for Angular templates. Prior to 21.2.4, the client-side Angular Language Service VS Code extension reads the custom TypeScript SDK paths typescript.tsdk and js/ts.tsdk.path directly from workspace configurations (.vscode/settings.json) without verifying VS Code Workspace Trust state or asking for user consent (located in client/src/client.ts). The client-side extension then passes the parsed settings path as a command-line argument (--tsdk) to the background Node.js language server process. During server initialization, the background language server resolves and dynamically imports (via standard Node.js require()) the module library tsserverlibrary.js relative to the workspace-specified custom directory path. An attacker can exploit this behavior by committing a repository containing a local malicious tsserverlibrary.js script inside a custom folder, and a crafted .vscode/settings.json file pointing to that folder. When a developer opens the repository folder in VS Code, the extension automatically attempts to initialize and load the server, which dynamically resolves, loads, and executes the malicious script silently in the background. This vulnerability is fixed in 21.2.4.

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to versions 19.2.21, 20.3.19, 21.2.9, and 22.0.0-next.8, a Server-Side Request Forgery (SSRF) vulnerability exists in @angular/platform-server due to improper handling of URLs during Server-Side Rendering (SSR). When an attacker sends a request such as GET /\evil.com/ HTTP/1.1 the server engine (Express, etc.) passes the URL string to Angular’s rendering functions. Because the URL parser normalizes the backslash to a forward slash for HTTP/HTTPS schemes, the internal state of the application is hijacked to believe the current origin is evil.com. This misinterpretation tricks the application into treating the attacker’s domain as the local origin. Consequently, any relative HttpClient requests or PlatformLocation.hostname references are redirected to the attacker controlled server, potentially exposing internal APIs or metadata services. This issue has been patched in versions 19.2.21, 20.3.19, 21.2.9, and 22.0.0-next.8.