In the second and third quarters of 2025, Google collaborated with Intel to conduct a security assessment of Intel Trust Domain Extensions (TDX), extending Google's previous review and covering major changes since Intel TDX Module 1.0 - namely support for Live Migration and Trusted Domain (TD) Partitioning (nested VMs within TDs). Intel provided guidance and support, including documentation and updated TDX 1.5 source code. Unlike the previous review, this time, we had access to a compute node capable of running TDX to develop a toolkit for live testing and Proof-of-Concept (PoC) generation. Furthermore, we integrated Gemini for analysis and NotebookLM to efficiently navigate complex specifications. This assessment resulted in the discovery of one vulnerability that enables a VMM to fully compromise a TD, and four vulnerabilities that enable a malicious VMM or TD to leak confidential memory of the Intel TDX Module. Several other security weaknesses and/or bugs were identified but not categorized as vulnerabilities despite having some impact on security. Beyond presenting the technical details of multiple bugs and vulnerabilities in this report, these findings underscore that confidential computing, like other security measures, requires iterative refinement and complementary security controls to harden it, in line with a defense-in-depth approach.

翻译：2025年第二、三季度，谷歌与英特尔合作，对英特尔可信域扩展（TDX）进行了安全评估。此项工作延续了谷歌先前对英特尔TDX模块1.0的审查，并涵盖了自该版本以来的主要变更——即对实时迁移与可信域（TD）分区（TD内的嵌套虚拟机）的支持。英特尔提供了指导与支持，包括相关文档及更新后的TDX 1.5源代码。与先前评估不同，本次我们得以使用一台能够运行TDX的计算节点，以开发用于实时测试和概念验证（PoC）生成的工具包。此外，我们集成了Gemini进行分析，并利用NotebookLM高效梳理复杂的规范文档。本次评估发现了一个可使虚拟机监控程序（VMM）完全攻陷TD的漏洞，以及四个可使恶意VMM或TD泄露英特尔TDX模块机密内存的漏洞。我们还识别出若干其他安全弱点和/或程序缺陷，这些虽对安全性有一定影响但未被归类为漏洞。本报告不仅呈现了多个程序缺陷与漏洞的技术细节，这些发现也进一步表明：与纵深防御理念一致，机密计算与其他安全措施一样，需要通过迭代优化与互补性的安全控制来持续加固。