Back to Security Bulletins and Briefs

AMD Response to “ZENHAMMER: Rowhammer Attacks on AMD Zen-Based Platforms”

AMD ID:    AMD-SB-7021
Potential Impact: Memory integrity
Severity: N/A

Summary

On February 26, 2024, AMD received new research related to an industry-wide DRAM issue documented in “ZENHAMMER: Rowhammering Attacks on AMD Zen-based Platforms” from researchers at ETH Zurich. The research demonstrates performing Rowhammer attacks on DDR4 and DDR5 memory using AMD “Zen” platforms. Given the history around Rowhammer, the researchers do not consider these rowhammering attacks to be a new issue.

Mitigation

AMD continues to assess the researchers’ claim of demonstrating Rowhammer bit flips on a DDR5 device for the first time. AMD will provide an update upon completion of its assessment.

AMD microprocessor products include memory controllers designed to meet industry-standard DDR specifications. Susceptibility to Rowhammer attacks varies based on the DRAM device, vendor, technology, and system settings. AMD recommends contacting your DRAM or system manufacturer to determine any susceptibility to this new variant of Rowhammer. 

AMD also continues to recommend the following existing DRAM mitigations to Rowhammer-style attacks, including:

  • Using DRAM supporting Error Correcting Codes (ECC)
  • Using memory refresh rates above 1x
  • Disabling Memory Burst/Postponed Refresh
  • Using AMD CPUs with memory controllers that support a Maximum Activate Count (MAC) (DDR4)
    • 1st Gen AMD EPYC™ Processors formerly codenamed “Naples"
    • 2nd Gen AMD EPYC™ Processors formerly codenamed “Rome"
    • 3rd Gen AMD EPYC™ Processors formerly codenamed “Milan"
    • AMD Ryzen™ 3000 Series Desktop Processors formerly codenamed "Matisse"
    • AMD Athlon™ 3000 Series Desktop Processors with Radeon™ Graphics formerly codenamed "Picasso AM4"
    • AMD Athlon™ 3000 Series Mobile Processors with Radeon™ Graphics formerly codenamed "Dali”/”Pollock"
    • AMD Ryzen™ 3000 Series Mobile Processor with Radeon™ Graphics formerly codenamed "Picasso FP5"
    • AMD Ryzen™ 3000 Series Processors with Radeon™ Graphics formerly codenamed "Barcelo-R"
    • AMD Ryzen™ 4000 Series Desktop Processors with Radeon™ Graphics formerly codenamed "Renoir AM4"
    • AMD Ryzen™ 4000 Series Mobile Processors with Radeon™ Graphics formerly codenamed "Renoir FP6"
    • AMD Ryzen™ 5000 Series Desktop Processors formerly codenamed "Vermeer"
    • AMD Ryzen™ 5000 Series Desktop Processors with Radeon™ Graphics formerly codenamed "Cezanne AM4"
    • AMD Ryzen™ 5000 Series Mobile Processors with Radeon™ Graphics formerly codenamed "Cezanne FP6"/ "Lucienne"
    • AMD Ryzen™ 5000 Series Processors with Radeon™ Graphics formerly codenamed "Barcelo"
    • AMD Ryzen™ Threadripper™ 3000 Series Processors formerly codenamed "Castle Peak HEDT"
    • AMD Ryzen™ Threadripper™ 5000 Series Processors formerly codenamed "Chagall HEDT"
    • AMD Ryzen™ Threadripper™ PRO 3000WX Series Processors formerly codenamed "Castle Peak WS"
    • AMD Ryzen™ Threadripper™ PRO 5000WX processors formerly codenamed "Chagall WS"
  • Using AMD CPUs with memory controllers that support Refresh Management (RFM) (DDR5)
    • 4th Gen AMD EPYC™ Processors formerly codenamed “Genoa"
    • AMD Ryzen™ 6000 Series Processors with Radeon™ Graphics formerly codenamed "Rembrandt"
    • AMD Ryzen™ 7000 Series Processors with Radeon™ Graphics formerly codenamed "Raphael X3D"/”Raphael”
    • AMD Ryzen™ 7035 Series Processors with Radeon™ Graphics formerly codenamed "Rembrandt-R"
    • AMD Ryzen™ 7040 Series Processors with Radeon™ Graphics formerly codenamed "Phoenix”
    • AMD Ryzen™ 7045 Series Processors with Radeon™ Graphics formerly codenamed "Dragon Range"

Acknowledgement

AMD thanks ETH Zurich: Patrick Jattke, Max Wipfli, Flavien Solt, Michele Marazzi, Matej Boleskei, Kaveh Razavi for reporting their findings and engaging in coordinated vulnerability disclosure.

Revisions 

Revision Date 

Description 

2024-04-09

 Added Client products to the Mitigation section

2024-03-25

Initial publication 

DISCLAIMER

The information contained herein is for informational purposes only and is subject to change without notice. While every precaution has been taken in the preparation of this document, it may contain technical inaccuracies, omissions and typographical errors, and AMD is under no obligation to update or otherwise correct this information. Advanced Micro Devices, Inc. makes no representations or warranties with respect to the accuracy or completeness of the contents of this document, and assumes no liability of any kind, including the implied warranties of noninfringement, merchantability or fitness for particular purposes, with respect to the operation or use of AMD hardware, software or other products described herein. Any computer system has risks of security vulnerabilities that cannot be completely prevented or mitigated. No license, including implied or arising by estoppel, to any intellectual property rights is granted by this document. Terms and limitations applicable to the purchase or use of AMD’s products are as set forth in a signed agreement between the parties or in AMD's Standard Terms and Conditions of Sale.

AMD, the AMD Arrow logo, EPYC, Radeon, Ryzen, Threadripper and combinations thereof are trademarks of Advanced Micro Devices, Inc. CVE and the CVE logo are registered trademarks of The MITRE Corporation. Other product names used in this publication are for identification purposes only and may be trademarks of their respective companies.

Third party content may be licensed to you directly by the third party that owns the content and is not licensed to you by AMD. ALL LINKED THIRD-PARTY CONTENT IS PROVIDED ‘AS IS’ WITHOUT A WARRANTY OF ANY KIND. USE OF SUCH THIRD-PARTY CONTENT IS DONE AT YOUR SOLE DISCRETION AND UNDER NO CIRCUMSTANCES WILL AMD BE LIABLE TO YOU FOR ANY THIRD-PARTY CONTENT. YOU ASSUME ALL RISK AND ARE SOLELY RESPONSIBILITY FOR ANY DAMAGES THAT MAY ARISE FROM YOUR USE OF THIRD-PARTY CONTENT.

© 2024 Advanced Micro Devices, Inc. All rights reserved.