How severe is CVE-2018-21133?

CVE-2018-21133 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-2018-21133 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-21133?

CVE-2018-21133 primarily affects Netgear Wac505 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-2018-21133?

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-2018-21133 published?

CVE-2018-21133 was published on 2020-04-23 and last updated on 2026-06-17.

CVE-2018-21133

CVE-2018-21133 is a critical-severity vulnerability in Netgear Wac505 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-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (68th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Netgear Wac505 Firmware
Published: 2020-04-23
Last modified: 2026-06-17

Description

Certain NETGEAR devices are affected by a stack-based buffer overflow by an unauthenticated attacker. This affects WAC505 before 5.0.0.17 and WAC510 before 5.0.0.17.

Frequently asked questions

What is CVE-2018-21133?: Certain NETGEAR devices are affected by a stack-based buffer overflow by an unauthenticated attacker. This affects WAC505 before 5.0.0.17 and WAC510 before 5.0.0.17.
How severe is CVE-2018-21133?: CVE-2018-21133 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-2018-21133 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-21133?: CVE-2018-21133 primarily affects Netgear Wac505 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-2018-21133?: 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-2018-21133 published?: CVE-2018-21133 was published on 2020-04-23 and last updated on 2026-06-17.

References

https://kb.netgear.com/000060227/Security-Advisory-for-Pre-Authentication-Stack-Overflow-on-Some-Wireless-Access-Points-PSV-2018-0326

Affected products (2)

cpe:2.3:o:netgear:wac505_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:wac510_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Netgear Wac505 Firmware

CVE-2018-21097 — Critical (CVSS 9.8): Certain NETGEAR devices are affected by a stack-based buffer overflow by an unauthenticated attacker. This affects…
CVE-2018-21132 — Critical (CVSS 9.8): Certain NETGEAR devices are affected by authentication bypass. This affects WAC505 before 5.0.0.17 and WAC510 before…
CVE-2018-21131 — Critical (CVSS 9.1): Certain NETGEAR devices are affected by unauthenticated firmware downgrade. This affects WAC505 before 5.0.0.17 and…
CVE-2018-21130 — High (CVSS 8.8): Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects WAC505 before…
CVE-2018-21128 — High (CVSS 8.8): Certain NETGEAR devices are affected by authentication bypass. This affects WAC505 before 5.0.0.17 and WAC510 before…
CVE-2018-21127 — High (CVSS 8.8): Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects WAC505 before…

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