CVE-2025-64095: 
C# vulnerability analysis and mitigation

The DNN Platform, a leading open-source Content Management System (CMS) in the Microsoft ecosystem, has disclosed a critical vulnerability (CVE-2025-64095) affecting all versions prior to 10.1.1. The vulnerability was discovered in the default HTML editor provider, which allows unauthenticated file uploads and enables images to overwrite existing files (GitHub Advisory, Security Online).

The vulnerability has been assigned a CVSS v3.1 score of 10.0, indicating the highest possible severity. The CVSS vector is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H, which indicates that the vulnerability can be exploited over the network, requires low attack complexity, needs no privileges or user interaction, and can affect resources beyond its security scope with high impact on confidentiality, integrity, and availability (GitHub Advisory, Miggo).

The vulnerability allows an unauthenticated attacker to upload and replace existing files on the server, potentially leading to website defacement. When combined with other vulnerabilities, it can enable the injection of Cross-Site Scripting (XSS) payloads, which can be stored and served to other users, including administrators, potentially leading to session hijacking and credential theft (Security Online).

The vulnerability has been patched in DNN Platform version 10.1.1. Administrators are strongly advised to update their installations immediately to this version. Site owners should also review their file logs for any unauthorized or suspicious file uploads or modifications if they were running an unpatched version (Security Online).