DotVVM is an open source MVVM framework for web applications. Prior to 4.2.11, 4.3.15, and 5.0.0-preview09-final, a route containing multiple unconstrained parameters in one path segment can cause excessive regular-expression backtracking in DotvvmRoute.IsMatch when a remote requester supplies a long near-match path. DotvvmRouteParser.RouteRegex previously had no matching timeout. Patched runtimes retry with the .NET non-backtracking engine, while runtimes that do not support non-backtracking matching return HTTP 503 after the one-second timeout in DotvvmRoutingMiddleware. This issue is fixed in versions 4.2.11, 4.3.15, and 5.0.0-preview09-final.

DotVVM is an open source MVVM framework for web applications. Prior to 4.2.11, 4.3.15, and 5.0.0-preview09-final, applications with configured file upload storage allow unauthenticated users to submit files directly to DotvvmFileUploadMiddleware without an X-DotVVM-UploadToken generated by the FileUpload component. An attacker can repeatedly upload files and fill application storage, causing denial of service. DotvvmConfiguration.Security.AuthorizeFileUpload can additionally restrict which users may upload files. This issue is fixed in versions 4.2.11, 4.3.15, and 5.0.0-preview09-final.