How severe is CVE-2021-45609?

CVE-2021-45609 has a CVSS 3.x base score of 9.6, rated critical 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-2021-45609 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-45609?

CVE-2021-45609 primarily affects Netgear D8500 Firmware. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-45609?

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-2021-45609 published?

CVE-2021-45609 was published on 2021-12-26 and last updated on 2026-06-17.

CVE-2021-45609

CVE-2021-45609 is a critical-severity vulnerability in Netgear D8500 Firmware with a CVSS 3.x base score of 9.6. 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 9.6)
CVSS v2: 7.5
EPSS exploit prediction: 1% (64th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Netgear D8500 Firmware
Published: 2021-12-26
Last modified: 2026-06-17

Description

Certain NETGEAR devices are affected by a buffer overflow by an unauthenticated attacker. This affects D8500 before 1.0.3.58, R6250 before 1.0.4.48, R7000 before 1.0.11.116, R7100LG before 1.0.0.64, R7900 before 1.0.4.38, R8300 before 1.0.2.144, R8500 before 1.0.2.144, XR300 before 1.0.3.68, R7000P before 1.3.2.132, and R6900P before 1.3.2.132.

Frequently asked questions

What is CVE-2021-45609?: Certain NETGEAR devices are affected by a buffer overflow by an unauthenticated attacker. This affects D8500 before 1.0.3.58, R6250 before 1.0.4.48, R7000 before 1.0.11.116, R7100LG before 1.0.0.64, R7900 before 1.0.4.38, R8300 before 1.0.2.144, R8500 before 1.0.2.144, XR300 before 1.0.3.68, R7000P before 1.3.2.132, and R6900P before 1.3.2.132.
How severe is CVE-2021-45609?: CVE-2021-45609 has a CVSS 3.x base score of 9.6, rated critical 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-2021-45609 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-45609?: CVE-2021-45609 primarily affects Netgear D8500 Firmware. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-45609?: 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-2021-45609 published?: CVE-2021-45609 was published on 2021-12-26 and last updated on 2026-06-17.

References

https://kb.netgear.com/000064483/Security-Advisory-for-Pre-Authentication-Buffer-Overflow-on-Some-Routers-PSV-2020-0274

Affected products (10)

cpe:2.3:o:netgear:d8500_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r6250_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r7000_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r7000p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r6900p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r7900_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r8300_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r8500_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:r7100lg_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:xr300_firmware:*:*:*:*:*:*:*:*

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