Executive brief
DotVVM, a framework for building web applications, contains a vulnerability that allows unauthorized users to upload files to the server. An attacker could exploit this to fill up the server's disk space, potentially causing the application or the entire server to crash. This impacts the availability of the service and could disrupt business operations.
Technical details
An unrestricted file upload vulnerability (CWE-434) exists in DotVVM when file upload storage is configured. The framework previously allowed any network-based attacker to upload files without requiring a cryptographic token or specific authorization. This can be exploited to perform a Denial of Service (DoS) attack by filling the server's storage capacity. The issue is resolved in versions 4.2.11, 4.3.15, and 5.0.0-preview09 by requiring a cryptographic token generated by the FileUpload component for all upload requests. Additionally, a new configuration option 'AuthorizeFileUpload' has been introduced to allow developers to restrict upload capabilities to specific authorized users.
Affected products
- Riganti DotVVM < 4.2.11, > 4.3.0-preview01-final, < 4.3.15, >= 5.0.0-preview01-final, < 5.0.0-preview09-final
Timeline
- 2026-06-18: disclosed: Advisory published by maintainer
- 2026-06-19: advisory: GitHub Advisory published