How severe is CVE-2021-33268?

CVE-2021-33268 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-2021-33268 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33268?

CVE-2021-33268 affects Dlink Dir-809 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-33268?

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-2021-33268 published?

CVE-2021-33268 was published on 2021-12-01 and last updated on 2026-06-17.

CVE-2021-33268

CVE-2021-33268 is a critical-severity vulnerability in Dlink Dir-809 Firmware with a CVSS 3.x base score of 9.8. 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-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Dlink Dir-809 Firmware
Published: 2021-12-01
Last modified: 2026-06-17

Description

D-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer overflow vulnerability in the function sub_8003183C in /fromLogin. This vulnerability is triggered via a crafted POST request.

Frequently asked questions

What is CVE-2021-33268?: D-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer overflow vulnerability in the function sub_8003183C in /fromLogin. This vulnerability is triggered via a crafted POST request.
How severe is CVE-2021-33268?: CVE-2021-33268 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-2021-33268 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33268?: CVE-2021-33268 affects Dlink Dir-809 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-33268?: 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-2021-33268 published?: CVE-2021-33268 was published on 2021-12-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:dlink:dir-809_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Dlink Dir-809 Firmware

CVE-2021-33274 — Critical (CVSS 9.8): D-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer…
CVE-2021-33271 — Critical (CVSS 9.8): D-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer…
CVE-2021-33270 — Critical (CVSS 9.8): D-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer…
CVE-2021-33269 — Critical (CVSS 9.8): D-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer…
CVE-2021-33267 — Critical (CVSS 9.8): D-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer…
CVE-2021-33266 — Critical (CVSS 9.8): D-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer…

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