K60570139 : Rowhammer hardware vulnerability CVE-2020-10255

Security Advisory Description

Modern DRAM chips (DDR4 and LPDDR4 after 2015) are affected by a vulnerability in deployment of internal mitigations against RowHammer attacks known as Target Row Refresh (TRR), aka the TRRespass issue. To exploit this vulnerability, the attacker needs to create certain access patterns to trigger bit flips on affected memory modules, aka a Many-sided RowHammer attack. This means that, even when chips advertised as RowHammer-free are used, attackers may still be able to conduct privilege-escalation attacks against the kernel, conduct privilege-escalation attacks against the Sudo binary, and achieve cross-tenant virtual-machine access by corrupting RSA keys. The issue affects chips produced by SK Hynix, Micron, and Samsung. NOTE: tracking DRAM supply-chain issues is not straightforward because a single product model from a single vendor may use DRAM chips from different manufacturers. (CVE-2020-10255)

Impact

This vulnerability impacts BIG-IP iSeries platforms and VIPRION B4450 blades only.

An unprivileged system user may leverage this flaw and use rowhammer attack variants to induce bit corruptions across memory space, potentially resulting in a denial of service or privileges escalation scenarios. The highest threat from this vulnerability is to system availability.