How severe is CVE-2018-21153?

CVE-2018-21153 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-21153 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-21153?

CVE-2018-21153 primarily affects Netgear D7800 Firmware. In total, 20 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-21153?

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

When was CVE-2018-21153 published?

CVE-2018-21153 was published on 2020-04-27 and last updated on 2026-06-17.

CVE-2018-21153

CVE-2018-21153 is a critical-severity vulnerability in Netgear D7800 Firmware with a CVSS 3.x base score of 9.8. 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: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Netgear D7800 Firmware
Published: 2020-04-27
Last modified: 2026-06-17

Description

Certain NETGEAR devices are affected by a buffer overflow by an unauthenticated attacker. This affects D7800 before 1.0.1.34, DM200 before 1.0.0.50, EX2700 before 1.0.1.32, EX6100v2 before 1.0.1.70, EX6150v2 before 1.0.1.70, EX6200v2 before 1.0.1.62, EX6400 before 1.0.1.78, EX7300 before 1.0.1.62, EX8000 before 1.0.0.114, R6100 before 1.0.1.22, R7500 before 1.0.0.122, R7500v2 before 1.0.3.26, R7800 before 1.0.2.40, R8900 before 1.0.3.10, R9000 before 1.0.3.10, WN2000RPTv3 before 1.0.1.26, WN3000RPv2 before 1.0.0.56, WN3000RPv3 before 1.0.2.66, WN3100RPv2 before 1.0.0.56, WNDR4300 before 1.0.2.98, WNDR4300v2 before 1.0.0.54, WNDR4500v3 before 1.0.0.54, and WNR2000v5 before 1.0.0.64.

Frequently asked questions

What is CVE-2018-21153?: Certain NETGEAR devices are affected by a buffer overflow by an unauthenticated attacker. This affects D7800 before 1.0.1.34, DM200 before 1.0.0.50, EX2700 before 1.0.1.32, EX6100v2 before 1.0.1.70, EX6150v2 before 1.0.1.70, EX6200v2 before 1.0.1.62, EX6400 before 1.0.1.78, EX7300 before 1.0.1.62, EX8000 before 1.0.0.114, R6100 before 1.0.1.22, R7500 before 1.0.0.122, R7500v2 before 1.0.3.26, R7800 before 1.0.2.40, R8900 before 1.0.3.10, R9000 before 1.0.3.10, WN2000RPTv3 before 1.0.1.26, WN3000RPv2 before 1.0.0.56, WN3000RPv3 before 1.0.2.66, WN3100RPv2 before 1.0.0.56, WNDR4300 before 1.0.2.98, WNDR4300v2 before 1.0.0.54, WNDR4500v3 before 1.0.0.54, and WNR2000v5 before 1.0.0.64.
How severe is CVE-2018-21153?: CVE-2018-21153 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-21153 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-21153?: CVE-2018-21153 primarily affects Netgear D7800 Firmware. In total, 20 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-21153?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2018-21153 published?: CVE-2018-21153 was published on 2020-04-27 and last updated on 2026-06-17.

References

https://kb.netgear.com/000059480/Security-Advisory-for-Pre-Authentication-Buffer-Overflow-on-Some-Gateways-Routers-and-Extenders-PSV-2017-3136

Affected products (20)

cpe:2.3:o:netgear:d7800_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:dm200_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex2700_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex6100_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex6150_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex6200_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex6400_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex7300_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:ex8000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r6100_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r7500_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r7800_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r8900_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r9000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:wn2000rpt_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:wn3000rp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:wn3100rp_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:wndr4300_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:wndr4500_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:wnr2000_firmware:*:*:*:*:*:*:*:*

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