How severe is CVE-2018-21171?

CVE-2018-21171 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-21171 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-21171?

CVE-2018-21171 primarily affects Netgear R7800 Firmware. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-21171?

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

When was CVE-2018-21171 published?

CVE-2018-21171 was published on 2020-04-27 and last updated on 2026-06-17.

CVE-2018-21171

CVE-2018-21171 is a medium-severity vulnerability in Netgear R7800 Firmware with a CVSS 3.x base score of 6.8. 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: Medium (CVSS 3.x base score 6.8)
CVSS v2: 5.2
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Netgear R7800 Firmware
Published: 2020-04-27
Last modified: 2026-06-17

Description

Certain NETGEAR devices are affected by a stack-based buffer overflow by an authenticated user. This affects D6100 before 1.0.0.57, R7800 before 1.0.2.40, R9000 before 1.0.3.6, WNDR3700v4 before 1.0.2.92, and WNDR4300 before 1.0.2.98.

Frequently asked questions

What is CVE-2018-21171?: Certain NETGEAR devices are affected by a stack-based buffer overflow by an authenticated user. This affects D6100 before 1.0.0.57, R7800 before 1.0.2.40, R9000 before 1.0.3.6, WNDR3700v4 before 1.0.2.92, and WNDR4300 before 1.0.2.98.
How severe is CVE-2018-21171?: CVE-2018-21171 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-21171 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-21171?: CVE-2018-21171 primarily affects Netgear R7800 Firmware. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-21171?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-21171 published?: CVE-2018-21171 was published on 2020-04-27 and last updated on 2026-06-17.

References

https://kb.netgear.com/000055187/Security-Advisory-for-Post-Authentication-Stack-Overflow-on-Some-Routers-and-Gateways-PSV-2017-2632

Affected products (5)

cpe:2.3:o:netgear:r7800_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r9000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:d6100_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:wndr3700_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:wndr4300_firmware:*:*:*:*:*:*:*:*

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