New ZenHammer Attack Bypasses RowHammer Defenses on AMD CPUs

Researchers at ETH Zurich published ZenHammer, a RowHammer variant that reverses DRAM address functions and uses optimized hammering to bypass TRR protections and trigger bit flips on multiple AMD Zen 2/3 systems and one DDR5-equipped Zen 4 device; the PoC shows partial success across tested hardware, raises concerns about broader AMD susceptibility given market share, and is under assessment by AMD.