CVE-2021-21554

Severity: medium (CVSS 6.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-06-14 · updated 2026-06-17
Weakness: CWE-122

Description

Dell PowerEdge R640, R740, R740XD, R840, R940, R940xa, MX740c, MX840c, and, Dell Precision 7920 Rack Workstation BIOS contain a stack-based buffer overflow vulnerability in systems with Intel Optane DC Persistent Memory installed. A local malicious user with high privileges may potentially exploit this vulnerability, leading to a denial of Service, arbitrary code execution, or information disclosure in UEFI or BIOS Preboot Environment.

Affected products

Dell Poweredge Mx740C Firmware: before 2.9.4 — fixed in 2.9.4
Dell Poweredge Mx840C Firmware: before 2.9.4 — fixed in 2.9.4
Dell Poweredge R640 Firmware: before 2.9.4 — fixed in 2.9.4
Dell Poweredge R740 Firmware: before 2.9.4 — fixed in 2.9.4
Dell Poweredge R740Xd Firmware: before 2.9.4 — fixed in 2.9.4
Dell Poweredge R840 Firmware: before 2.9.4 — fixed in 2.9.4
Dell Poweredge R940 Firmware: before 2.9.4 — fixed in 2.9.4
Dell Poweredge R940Xa Firmware: before 2.9.4 — fixed in 2.9.4
Dell Precision 7920 Firmware: all versions

How to fix

Upgrade to a fixed version: Dell Poweredge Mx740C Firmware 2.9.4; Dell Poweredge Mx840C Firmware 2.9.4; Dell Poweredge R640 Firmware 2.9.4; Dell Poweredge R740 Firmware 2.9.4; Dell Poweredge R740Xd Firmware 2.9.4; Dell Poweredge R840 Firmware 2.9.4; Dell Poweredge R940 Firmware 2.9.4; Dell Poweredge R940Xa Firmware 2.9.4. Check the vendor advisory for mitigations.

References

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