New DDRop Attack Breaks Intel TDX and AMD SEV-SNP Confidential Computing

The DDRop attack exploits a physical hardware vulnerability by inserting a custom interposer circuit between the CPU and memory modules, silently dropping memory write operations so the processor reads stale, outdated encrypted data. This undermines the core integrity guarantees that confidential computing technologies like Intel TDX and AMD SEV-SNP are designed to provide, potentially allowing an attacker with physical or supply-chain access to hijack protected virtual machines. The attack is particularly dangerous in cloud and data center environments where tenants rely on hardware-enforced isolation to protect sensitive workloads from even privileged insiders. This highlights that cryptographic and software-layer protections are insufficient when physical hardware integrity cannot be guaranteed, making supply chain security and physical access controls critical.