A team of security researchers has identified an architectural flaw in modern memory encryption hardware. The vulnerability allows unauthorized access to protected memory areas in confidential computing environments, provided the attacker has physical access to the system.
The researchers developed a hardware module named DDRop, which costs $200. The device connects between the processor and DDR5 memory, intercepting write operations to feed the virtual machine outdated data without its knowledge.
The attack compromises security mechanisms including Intel TDX, Scalable SGX, and AMD SEV-SNP. By injecting data into page tables, the method forces virtual machines into debug mode, allowing the extraction of memory contents in plaintext.
The DDRop module can modify DDR5 bus traffic without impacting performance. It also enables the forgery of attestation reports, allowing a compromised virtual machine to appear legitimate to remote users.
Intel and AMD have acknowledged the vulnerability but stated it falls outside their threat models for cloud computing. Both companies have confirmed they do not intend to release hardware or software patches to address the issue.
