Intel TDX

DDRop: a $159 DDR5 hardware interposer silently drops targeted memory writes, defeating Intel TDX/SGX and AMD SEV-SNP integrity guarantees, with no vendor fix

Researchers from KU Leuven, ETH Zurich, Durham University and Google disclosed DDRop, an open-source DDR5 hardware interposer that costs about $159 in parts and, unlike earlier passive interposers, runs at native bus speed (DDRop research team, 2026-09-14). It forges a parity error on a targeted write and suppresses the alert, so the memory module silently drops the write and stale, attacker-chosen ciphertext stays in place. Against Intel TDX this corrupts the TDX module's initialization of Secure Extended Page Tables, so an attacker-controlled Trust Domain can remap its memory onto other physical memory. Under TDX's default logical integrity mode that lets the attacker flip a victim Trust Domain's debug attribute and read its memory through the hypervisor's debug API, and even under cryptographic integrity mode the attacker can forge the launch measurement of a rogue VM of their own so that it passes remote attestation (DDRop research team, 2026-09-14).

The attack needs a brief, one-time visit to install the interposer, which takes minutes, on top of the standard confidential-computing threat model in which the adversary controls the hypervisor and BIOS. The researchers name data-center insiders, supply-chain tampering and hardware access compelled by law enforcement or governments as ways to get that access (DDRop research team, 2026-09-14). Intel and AMD both place physical attacks on the memory bus outside their threat models; AMD does not plan to assign a CVE, and Intel is evaluating further hardening and detection options (Intel PSIRT, 2026-09-14; AMD Product Security, 2026-09-15). Schematics, board files, firmware and proof-of-concept code are public (DDRop research team, 2026-09-14), and no in-the-wild use is claimed.