What is CVE-2021-40284?

CVE-2021-40284 is a medium-severity vulnerability in Dlink Dsl-3782, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 6.5/10. Published 2021-09-09.

How severe is CVE-2021-40284?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Buffer overflow in Dlink Dsl-3782

CVE-2021-40284

D-Link DSL-3782 EU v1.01:EU v1.03 is affected by a buffer overflow which can cause a denial of service. This vulnerability exists in the web interface "/cgi-bin/New_GUI/Igmp.asp". Authenticated remote attackers can trigger this vulnerability by sending a long string in parameter 'igmpsnoopEnable' via an HTTP request.

Vulnerability class: Buffer Overflow

Published 2021-09-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.026 (85.0th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 85th percentile — 85.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.026 · newest: 0.026 · change: 0.000

Affected products

Dlink Dsl-3782
Dlink Dsl-3782 Firmware — versions eu_1.01, eu_1.03

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

www.dlink.com/en/security-bulletin/ (Vendor Advisory)
supportannouncement.us.dlink.com/announcement/publication.aspx (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-40284?: CVE-2021-40284 is a medium-severity vulnerability in Dlink Dsl-3782, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 6.5/10. Published 2021-09-09.
How severe is CVE-2021-40284?: Medium severity. CVSS v3 base score is 6.5 out of 10.