When Mitigations Backfire: Timing Channel Attacks and Defense for PRAC-Based RowHammer Mitigations

Per Row Activation Counting PRAC has emerged as a robust framework for mitigating RowHammer RH vulnerabilities in modern DRAM systems. However, we uncover a critical vulnerability: a timing channel introduced by the Alert Back-Off ABO protocol and Refresh Management RFM commands. We present...