CVE-2021-42114: micron ddr4_sdram_firmware Improper Input Validation

Vulnerability summary

CVE-2021-42114 is a critical (CVSS 9.0) Improper Input Validation vulnerability in micron ddr4_sdram_firmware. EPSS estimates a 2.98% chance of exploitation in the next 30 days, higher than 87.1% of scored vulnerabilities. 3 public exploits are recorded.

Timeline

1. 16-11-2021
   PublishedVulnerability first disclosed.
2. 17-09-2024
   Last modifiedVulnerability information updated.

Description

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.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.