# CVE-2021-42114: Scalable Rowhammering In the Frequency Domain to Bypass TRR Mitigations On Modern DDR4/LPDDR4X Devices


- **Severity:** Critical 9.0 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 16 Nov 2021
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-6wv8-rx52-7p78

## What is CVE-2021-42114?

CVE-2021-42114 is a critical vulnerability in Micron ddr4_sdram, published on 16 Nov 2021. 

### Official 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.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2021-42114?

It affects 6 products.


Products: Micron Ddr4 Sdram Firmware, Micron Lddr4 Firmware, Samsung Ddr4 Sdram Firmware, Samsung Lddr4 Firmware, Skhynix Ddr4 Sdram Firmware, Skhynix Lddr4 Firmware.

## How do I fix CVE-2021-42114?

No fix has been published for CVE-2021-42114 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-42114 being exploited?

There is no known exploitation of CVE-2021-42114 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-42114 and fix it if it is affected.

What it is: CVE-2021-42114 is a critical vulnerability in Micron ddr4_sdram, published on 16 Nov 2021. 
Exploitation: There is no known exploitation of CVE-2021-42114 in the wild and no public exploit code.

Affected product: Micron ddr4_sdram. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-42114/ (Markdown: https://insights.sbomify.com/CVE-2021-42114/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-42114
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-42114
- OSV: https://osv.dev/vulnerability/CVE-2021-42114

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-42114/
Summaries are generated and may contain mistakes; the official description above is the record.