How severe is CVE-2021-27114?

CVE-2021-27114 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-27114 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 25% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27114?

CVE-2021-27114 affects Dlink Dir-816 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27114?

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

When was CVE-2021-27114 published?

CVE-2021-27114 was published on 2021-04-14 and last updated on 2026-06-17.

CVE-2021-27114

CVE-2021-27114 is a critical-severity vulnerability in Dlink Dir-816 Firmware with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 25% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 25% (98th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Dlink Dir-816 Firmware
Published: 2021-04-14
Last modified: 2026-06-17

Description

An issue was discovered in D-Link DIR-816 A2 1.10 B05 devices. Within the handler function of the /goform/addassignment route, a very long text entry for the"'s_ip" and "s_mac" fields could lead to a Stack-Based Buffer Overflow and overwrite the return address.

Frequently asked questions

What is CVE-2021-27114?: An issue was discovered in D-Link DIR-816 A2 1.10 B05 devices. Within the handler function of the /goform/addassignment route, a very long text entry for the"'s_ip" and "s_mac" fields could lead to a Stack-Based Buffer Overflow and overwrite the return address.
How severe is CVE-2021-27114?: CVE-2021-27114 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-27114 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 25% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27114?: CVE-2021-27114 affects Dlink Dir-816 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27114?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-27114 published?: CVE-2021-27114 was published on 2021-04-14 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:dlink:dir-816_firmware:1.10b05:*:*:*:*:*:*:*

More vulnerabilities in Dlink Dir-816 Firmware

CVE-2026-4184 — Critical (CVSS 9.8): A vulnerability was detected in D-Link DIR-816 1.10CNB05. Affected by this vulnerability is an unknown functionality of…
CVE-2026-4183 — Critical (CVSS 9.8): A security vulnerability has been detected in D-Link DIR-816 1.10CNB05. Affected is an unknown function of the file…
CVE-2026-4182 — Critical (CVSS 9.8): A weakness has been identified in D-Link DIR-816 1.10CNB05. This impacts an unknown function of the file…
CVE-2026-4181 — Critical (CVSS 9.8): A security flaw has been discovered in D-Link DIR-816 1.10CNB05. This affects an unknown function of the file…
CVE-2025-45931 — Critical (CVSS 9.8): An issue D-Link DIR-816-A2 DIR-816A2_FWv1.10CNB05_R1B011D88210 allows a remote attacker to execute arbitrary code via…
CVE-2025-5630 — Critical (CVSS 9.8): A vulnerability has been found in D-Link DIR-816 1.10CNB05 and classified as critical. This vulnerability affects…

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