Uncovering In-DRAM RowHammer Protection Mechanisms: A New Methodology, Custom RowHammer Patterns, and Implications

Understand

The RowHammer vulnerability in DRAM is a critical threat to system security.

• To protect against RowHammer, vendors commit to security-through-obscurity: modern DRAM chips rely on undocumented, proprietary, on-die mitigations, commonly known as Target Row Refresh (TRR).
• At a high level, TRR detects and refreshes potential RowHammer-victim rows, but its exact implementations are not openly disclosed.
• Security guarantees of TRR mechanisms cannot be easily studied due to their proprietary nature.