How severe is CVE-2018-21218?

CVE-2018-21218 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-21218 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-21218?

CVE-2018-21218 primarily affects Netgear Wnr2000 Firmware. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-21218?

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

When was CVE-2018-21218 published?

CVE-2018-21218 was published on 2020-04-28 and last updated on 2026-06-17.

CVE-2018-21218

CVE-2018-21218 is a high-severity vulnerability in Netgear Wnr2000 Firmware with a CVSS 3.x base score of 8.8. 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-120.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 5.8
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Netgear Wnr2000 Firmware
Published: 2020-04-28
Last modified: 2026-06-17

Description

Certain NETGEAR devices are affected by a buffer overflow by an unauthenticated attacker. This affects D3600 before 1.0.0.67, D6000 before 1.0.0.67, D6100 before 1.0.0.56, D7800 before 1.0.1.30, R6100 before 1.0.1.20, R7500 before 1.0.0.118, R7500v2 before 1.0.3.24, R9000 before 1.0.2.52, WNDR3700v4 before 1.0.2.96, WNDR4300 before 1.0.2.98, WNDR4300v2 before 1.0.0.50, WNDR4500v3 before 1.0.0.50, and WNR2000v5 before 1.0.0.62.

Frequently asked questions

What is CVE-2018-21218?: Certain NETGEAR devices are affected by a buffer overflow by an unauthenticated attacker. This affects D3600 before 1.0.0.67, D6000 before 1.0.0.67, D6100 before 1.0.0.56, D7800 before 1.0.1.30, R6100 before 1.0.1.20, R7500 before 1.0.0.118, R7500v2 before 1.0.3.24, R9000 before 1.0.2.52, WNDR3700v4 before 1.0.2.96, WNDR4300 before 1.0.2.98, WNDR4300v2 before 1.0.0.50, WNDR4500v3 before 1.0.0.50, and WNR2000v5 before 1.0.0.62.
How severe is CVE-2018-21218?: CVE-2018-21218 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-21218 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-21218?: CVE-2018-21218 primarily affects Netgear Wnr2000 Firmware. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-21218?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-21218 published?: CVE-2018-21218 was published on 2020-04-28 and last updated on 2026-06-17.

References

https://kb.netgear.com/000055119/Security-Advisory-for-Pre-Authentication-Buffer-Overflow-on-Some-Routers-and-Gateways-PSV-2017-2483

Affected products (11)

cpe:2.3:o:netgear:wnr2000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r9000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:wndr3700_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:wndr4300_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r7500_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:wndr4500_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r6100_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:d7800_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:d6000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:d3600_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:d6100_firmware:*:*:*:*:*:*:*:*

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