New ZenHammer Attack Bypasses RowHammer Defenses on AMD CPUs
Mar 28, 2024
Hardware Security / Vulnerability
Cybersecurity researchers from ETH Zurich have developed a new variant of the RowHammer DRAM (dynamic random-access memory) attack that, for the first time, successfully works against AMD Zen 2 and Zen 3 systems despite mitigations such as Target Row Refresh (TRR). "This result proves that AMD systems are equally vulnerable to Rowhammer as Intel systems, which greatly increases the attack surface, considering today's AMD market share of around 36% on x86 desktop CPUs," the researchers said . The technique has been codenamed ZenHammer , which can also trigger RowHammer bit flips on DDR5 devices for the first time. RowHammer , first publicly disclosed in 2014, is a well-known attack that exploits DRAM's memory cell architecture to alter data by repeatedly accessing a specific row (aka hammering) to cause the electrical charge of a cell to leak to adjacent cells. This can induce random bit flips in neighboring memory rows (from 0 to 1, or vice versa), which can