Описание
Modern DRAM devices (PC-DDR4, LPDDR4X) are affected by a vulnerability in their internal Target Row Refresh (TRR) mitigation against Rowhammer attacks. Novel non-uniform Rowhammer access patterns, consisting of aggressors with different frequencies, phases, and amplitudes allow triggering bit flips on affected memory modules using our Blacksmith fuzzer. The patterns generated by Blacksmith were able to trigger bitflips on all 40 PC-DDR4 DRAM devices in our test pool, which cover the three major DRAM manufacturers: Samsung, SK Hynix, and Micron. This means that, even when chips advertised as Rowhammer-free are used, attackers may still be able to exploit Rowhammer. For example, this enables privilege-escalation attacks against the kernel or binaries such as the sudo binary, and also triggering bit flips in RSA-2048 keys (e.g., SSH keys) to gain cross-tenant virtual-machine access. We can confirm that DRAM devices acquired in July 2020 with DRAM chips from all three major DRAM vendors (Samsung, SK Hynix, Micron) are affected by this vulnerability. For more details, please refer to our publication.
A Rowhammer flaw was found in the latest DDR4 DRAM hardware chips. This flaw is different from the previously known attack (CVE-2020-10255) by non-uniform patterns of memory access. These DDR4 DRAM hardware chips implement a Target Row Refresh (TRR) mitigation to prevent a Rowhammer flaw-induced bit corruption across memory space. This flaw allows an unprivileged system user to use Rowhammer attack variants to induce bit corruptions across memory space, potentially resulting in a denial of service or privileges escalation scenarios. With the currently known attack scenarios, the highest threat from this vulnerability is to system availability.
Отчет
Red Hat Product Security is aware of this issue. This is a hardware issue. It can not be fixed via usual software updates. For additional information, please refer to the Red Hat Knowledgebase article: https://access.redhat.com/articles/1377393
Меры по смягчению последствий
Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. One way of possible (but non practical) mitigation is to check if hardware vulnerable with existing reproducer blacksmith and if yes, then use some software (currently only prototype available) to prevent attacks: like ARMOR or ANVIL. The other possible mitigation is to prevent high CPU (or high memory or high network) usage, because the currently known fuzzer requires some very high-speed memory access for some reasonable time period.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 5 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Not affected |
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Дополнительная информация
Статус:
EPSS
8.3 High
CVSS3
Связанные уязвимости
Modern DRAM devices (PC-DDR4, LPDDR4X) are affected by a vulnerability in their internal Target Row Refresh (TRR) mitigation against Rowhammer attacks. Novel non-uniform Rowhammer access patterns, consisting of aggressors with different frequencies, phases, and amplitudes allow triggering bit flips on affected memory modules using our Blacksmith fuzzer. The patterns generated by Blacksmith were able to trigger bitflips on all 40 PC-DDR4 DRAM devices in our test pool, which cover the three major DRAM manufacturers: Samsung, SK Hynix, and Micron. This means that, even when chips advertised as Rowhammer-free are used, attackers may still be able to exploit Rowhammer. For example, this enables privilege-escalation attacks against the kernel or binaries such as the sudo binary, and also triggering bit flips in RSA-2048 keys (e.g., SSH keys) to gain cross-tenant virtual-machine access. We can confirm that DRAM devices acquired in July 2020 with DRAM chips from all three major DRAM vendors (S
Modern DRAM devices (PC-DDR4, LPDDR4X) are affected by a vulnerability in their internal Target Row Refresh (TRR) mitigation against Rowhammer attacks. Novel non-uniform Rowhammer access patterns, consisting of aggressors with different frequencies, phases, and amplitudes allow triggering bit flips on affected memory modules using our Blacksmith fuzzer. The patterns generated by Blacksmith were able to trigger bitflips on all 40 PC-DDR4 DRAM devices in our test pool, which cover the three major DRAM manufacturers: Samsung, SK Hynix, and Micron. This means that, even when chips advertised as Rowhammer-free are used, attackers may still be able to exploit Rowhammer. For example, this enables privilege-escalation attacks against the kernel or binaries such as the sudo binary, and also triggering bit flips in RSA-2048 keys (e.g., SSH keys) to gain cross-tenant virtual-machine access. We can confirm that DRAM devices acquired in July 2020 with DRAM chips from all three major DRAM vendors...
Уязвимость внутренней системы защиты целевой строки (TRR) устройства DRAM (PC-DDR4, LPDDR4X), позволяющая нарушителю повысить свои привилегии
EPSS
8.3 High
CVSS3