IT security researchers have unveiled DDROP, a hardware attack that uses a simple, inexpensive adapter plug to bypass the RAM encryption that underpins confidential computing — the technology cloud providers use to guarantee that even they cannot access customer data inside virtual machines.
The attack works by inserting a Teensy microcontroller-based adapter between a DDR5 memory stick and the motherboard slot. The device intercepts and silently drops write operations to memory by exploiting DDR5 error handling: it generates parity errors and suppresses the feedback, causing the memory module to discard the write command while the processor remains unaware anything went wrong.
Because old data persists in memory cells when writes are blocked, attackers can freeze a system’s state at a precise moment. When applied to Intel’s TDX (Trust Domain Extensions) technology, DDROP can manipulate the Secure Extended Page Tables that control how encrypted virtual machines access memory. The researchers demonstrated that this allows an attacker-controlled virtual machine to read and modify encrypted data from other virtual machines, or to bypass boot-time integrity checks entirely.
The attack affects Intel TDX, Intel Scalable SGX, AMD SEV-SNP, and potentially Arm CCA, though it was only tested against x86 platforms. The researchers notified all three chipmakers, who confirmed the findings but noted that physical DRAM attacks fall “out of scope” for their current threat models. Intel added that while it is out of scope, it is not “out of mind” and that the company is examining next-generation memory encryption with stronger hardware protection.
The implications are significant for cloud computing: confidential computing’s entire value proposition is that organizations can host sensitive data in untrusted environments without worrying about physical access by data center operators. DDROP’s simple, low-cost attack vector — a cheap adapter requiring no specialized equipment — undermines that promise. The attack also runs at full bus speed without slowing memory performance, making it harder to detect than previous approaches.
