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 show a cheap hardware add-on can forge Intel TDX attestation reports by tampering with memory writes at the DRAM bus
Analysis
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, 2026-09-14). 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.
Cited evidence
DDRop is a small, low-cost hardware interposer device that can make writes to a server's memory disappear, causing the computer to read old data as if it were newly written.
This primitive is 100% deterministic and lets an attacker-controlled TD remap its own memory onto any physical address in RAM.
Intel's analysis confirms that the described scenarios fall outside Intel's standard threat model for confidential computing deployments.
AMD has assessed this report and has determined that the described technique relies on a physical attack against the memory bus, which falls outside the scope of the published threat model for SEV-SNP. AMD does not plan to assign a CVE or release mitigations in response to this report.
Updates1
Intel and AMD acknowledged the findings and place physical attacks on the memory bus outside their threat models (DDRop research team, 2026-09-14). Only AMD says it does not plan to assign a CVE or release mitigations (AMD Product Security, 2026-09-14). Intel's announcement does not mention a CVE and says Intel is evaluating additional architectural hardening options and detection mechanisms (Intel PSIRT, 2026-09-14). The earlier statement that both vendors confirmed the findings and that neither is assigning a CVE went beyond what they published.
Sources4
Revision history
- Published 2026-09-17T0409Z-intel
- Correction 2026-09-30T0639Z-audit
Priority recalibrated from notable to routine: hardware research needing physical access, with no near-term decision for Swiss public bodies. The body is shortened to suit that priority, and the vendor positions are narrowed to what Intel and AMD published: AMD does not plan to assign a CVE or release mitigations, and Intel is evaluating further hardening. The title no longer says neither vendor assigns a CVE, since only AMD says so.
Changed: priority body summary title
AI-generated · no human review · this permalink is the shareable record for the finding · verify operationally critical claims against the linked primary source.