Skip to main content
No exploitation reported

CVE-2021-42114

No exploitation reported by the sources we read.

  • Published2021-11-16
  • WeaknessCWE-20

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2021-11-1612:15CVE publishedNVD

Versions per branch

NVD
Micron ddr4 sdram firmwareversion to verify
BranchAffectedFixed in
—all versionsno fix published
Micron lddr4 firmwareversion to verify
BranchAffectedFixed in
—all versionsno fix published
Samsung ddr4 sdram firmwareversion to verify
BranchAffectedFixed in
—all versionsno fix published

3 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • CVE-2021-42114 Red Hat Product Security

    hw: dram: new non-uniform circumvent TRR to induce bit flips via Rowhammer

Full record on NVD

Fix

  1. Workaround from the vendor Red Hat Product Security CVE-2021-42114 · 170 productsRed 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 (currentl…

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

  • CNACVSS 3.19known since 2026-10-23
  • NVDCVSS 3.18.3read 2026-10-23
  • NVDCVSS 2.07.9read 2026-10-23
  • CNAweakness (CWE)CWE-20known since 2026-10-23
  • FIRST EPSSEPSS score3.0 %2026-11-08
  • GitHub Advisoriesadvisory—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Published
2021-11-16
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-6wv8-rx52-7p78

Frequently asked questions

What is CVE-2021-42114?

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.

Is CVE-2021-42114 actively exploited?

Active exploitation of CVE-2021-42114 has not been confirmed. Its EPSS score was 3.0% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-42114?

CVE-2021-42114 has a CVSS v3 base score of 8.3 (HIGH severity), with vector string CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

Running hw? Hear about its next vulnerability

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this productCISA KEV additions, November 2026Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database

Sources for this record