Vulnerability record · CVE-2021-33269 · published 1 December 2021

CVE-2021-33269: Dlink dir-809 firmware out-of-bounds write vulnerability

Dlink · Dir 809 Firmware

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 FUN_8004776c in /formVirtualServ. This vulnerability is triggered via a crafted POST request.

9.8 CVSS 3.1 Critical EPSS 4.0% · top 9.9% CWE-787 · Out-of-bounds write

9.8CVSS 3.1 base score, v2 10.0

4.0%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

4References, 2 tagged exploit

17 Jun 2026Last modified by NVD

Description

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Dir 809 Firmware Dlink

References

Link	Tags
https://github.com/Lnkvct/IoT-poc/tree/master/D-Link-DIR809/vuln01	ExploitThird Party Advisory
https://www.dlink.com/en/security-bulletin/	Vendor Advisory
https://github.com/Lnkvct/IoT-poc/tree/master/D-Link-DIR809/vuln01	ExploitThird Party Advisory
https://www.dlink.com/en/security-bulletin/	Vendor Advisory

Track CVE-2021-33269 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2014-8361Realtek SDK miniigd SOAP service remote code executionThe miniigd SOAP service in the Realtek SDK fails to properly validate input in a NewInternalClient request, allowing remote code execution. The flaw…KEVEPSS 100%analysed1 May 2015 9.8CVE-2021-33265Dlink dir-809 firmware out-of-bounds write vulnerabilityD-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer overflow vulnerability in the f…EPSS 14%1 Dec 2021 9.8CVE-2021-33266Dlink dir-809 firmware out-of-bounds write vulnerabilityD-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer overflow vulnerability in the f…EPSS 17%1 Dec 2021 9.8CVE-2021-33267Dlink dir-809 firmware out-of-bounds write vulnerabilityD-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer overflow vulnerability in the f…EPSS 4.0%1 Dec 2021 9.8CVE-2021-33268Dlink dir-809 firmware out-of-bounds write vulnerabilityD-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer overflow vulnerability in the f…EPSS 4.1%1 Dec 2021 9.8CVE-2021-33270Dlink dir-809 firmware out-of-bounds write vulnerabilityD-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer overflow vulnerability in the f…EPSS 4.0%1 Dec 2021 9.8CVE-2021-33271Dlink dir-809 firmware out-of-bounds write vulnerabilityD-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer overflow vulnerability in the f…EPSS 4.0%1 Dec 2021 9.8CVE-2021-33274Dlink dir-809 firmware out-of-bounds write vulnerabilityD-Link DIR-809 devices with firmware through DIR-809Ax_FW1.12WWB03_20190410 were discovered to contain a stack buffer overflow vulnerability in the f…EPSS 4.0%1 Dec 2021

Source: NIST National Vulnerability Database (record CVE-2021-33269), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.