How severe is CVE-2021-40284?

CVE-2021-40284 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-40284 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-40284?

CVE-2021-40284 primarily affects Dlink Dsl-3782 Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-40284?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-40284 published?

CVE-2021-40284 was published on 2021-09-09 and last updated on 2026-06-17.

CVE-2021-40284

CVE-2021-40284 is a medium-severity vulnerability in Dlink Dsl-3782 Firmware with a CVSS 3.x base score of 6.5. 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-120.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 6.8
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Dlink Dsl-3782 Firmware
Published: 2021-09-09
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2021-40284?: CVE-2021-40284 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-40284 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-40284?: CVE-2021-40284 primarily affects Dlink Dsl-3782 Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-40284?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-40284 published?: CVE-2021-40284 was published on 2021-09-09 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:o:dlink:dsl-3782_firmware:eu_1.01:*:*:*:*:*:*:*
cpe:2.3:o:dlink:dsl-3782_firmware:eu_1.03:*:*:*:*:*:*:*

More vulnerabilities in Dlink Dsl-3782 Firmware

CVE-2018-8898 — Critical (CVSS 9.8): A flaw in the authentication mechanism in the Login Panel of router D-Link DSL-3782 (A1_WI_20170303 ||…
CVE-2023-44959 — High (CVSS 8.8): An issue found in D-Link DSL-3782 v.1.03 and before allows remote authenticated users to execute arbitrary code as root…
CVE-2023-27216 — High (CVSS 8.8): An issue found in D-Link DSL-3782 v.1.03 allows remote authenticated users to execute arbitrary code as root via the…
CVE-2022-34528 — High (CVSS 8.8): D-Link DSL-3782 v1.03 and below was discovered to contain a stack overflow via the function getAttrValue.
CVE-2022-34527 — High (CVSS 8.8): D-Link DSL-3782 v1.03 and below was discovered to contain a command injection vulnerability via the function…
CVE-2018-17990 — High (CVSS 8.8): An issue was discovered on D-Link DSL-3782 devices with firmware 1.01. An OS command injection vulnerability in Acl.asp…

All CVEs affecting Dlink Dsl-3782 Firmware →

Other CWE-120 (Classic Buffer Overflow) vulnerabilities

CVE-2025-48611 — Critical (CVSS 10.0): In DeviceId of DeviceId.java, there is a possible desync in persistence due to a missing bounds check. This could lead…
CVE-2026-24823 — Critical (CVSS 10.0): Out-of-bounds Write, Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in FASTSHIFT…
CVE-2026-24810 — Critical (CVSS 10.0): Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in rethinkdb (src/cjson modules).…
CVE-2026-24800 — Critical (CVSS 10.0): Out-of-bounds Write, Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in tildearrow…
CVE-2025-9962 — Critical (CVSS 10.0): A buffer overflow vulnerability in Novakon P series allows attackers to gain root permission without prior…
CVE-2010-10016 — Critical (CVSS 10.0): BS.Player version 2.57 (build 1051) contains a vulnerability in its playlist import functionality. When processing .m3u…

Browse all CWE-120 (Classic Buffer Overflow) vulnerabilities →