How severe is CVE-2021-21557?

CVE-2021-21557 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.

Is CVE-2021-21557 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21557?

CVE-2021-21557 primarily affects Dell Poweredge R640 Firmware. In total, 31 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-21557?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-21557 published?

CVE-2021-21557 was published on 2021-06-14 and last updated on 2026-06-17.

CVE-2021-21557

CVE-2021-21557 is a high-severity vulnerability in Dell Poweredge R640 Firmware with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 7.2
EPSS exploit prediction: 0% (27th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Dell Poweredge R640 Firmware
Published: 2021-06-14
Last modified: 2026-06-17

Description

Dell PowerEdge Server BIOS and select Dell Precision Rack BIOS contain an out-of-bounds array access vulnerability. 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 System Management Mode.

Frequently asked questions

What is CVE-2021-21557?: Dell PowerEdge Server BIOS and select Dell Precision Rack BIOS contain an out-of-bounds array access vulnerability. 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 System Management Mode.
How severe is CVE-2021-21557?: CVE-2021-21557 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.
Is CVE-2021-21557 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21557?: CVE-2021-21557 primarily affects Dell Poweredge R640 Firmware. In total, 31 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-21557?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-21557 published?: CVE-2021-21557 was published on 2021-06-14 and last updated on 2026-06-17.

References

https://www.dell.com/support/kbdoc/000187958

Affected products (31)

cpe:2.3:o:dell:poweredge_r640_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r740_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r740xd_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r940_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r540_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r440_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_t440_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_xr2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r740xd2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r840_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r940xa_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_t640_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_c6420_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_fc640_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_m640_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_m640p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_mx740c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_mx840c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_c4140_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_t140_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_t340_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r240_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r340_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r6415_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r7415_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r7425_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r6515_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r7515_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r6525_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_r7525_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:dell:poweredge_c6525_firmware:*:*:*:*:*:*:*:*

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