How severe is CVE-2018-21121?

CVE-2018-21121 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-2018-21121 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-21121?

CVE-2018-21121 primarily affects Netgear Gs810emx Firmware. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-21121?

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-2018-21121 published?

CVE-2018-21121 was published on 2020-04-22 and last updated on 2026-06-17.

CVE-2018-21121

CVE-2018-21121 is a high-severity vulnerability in Netgear Gs810emx 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-287.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 5.8
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Netgear Gs810emx Firmware
Published: 2020-04-22
Last modified: 2026-06-17

Description

Certain NETGEAR devices are affected by authentication bypass. This affects GS810EMX before 1.0.0.5, XS512EM before 1.0.0.6, and XS724EM before 1.0.0.6.

Frequently asked questions

What is CVE-2018-21121?: Certain NETGEAR devices are affected by authentication bypass. This affects GS810EMX before 1.0.0.5, XS512EM before 1.0.0.6, and XS724EM before 1.0.0.6.
How severe is CVE-2018-21121?: CVE-2018-21121 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-2018-21121 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-21121?: CVE-2018-21121 primarily affects Netgear Gs810emx Firmware. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-21121?: 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-2018-21121 published?: CVE-2018-21121 was published on 2020-04-22 and last updated on 2026-06-17.

References

https://kb.netgear.com/000060237/Security-Advisory-for-Authentication-Bypass-on-Some-Switches-PSV-2018-0219

Affected products (3)

cpe:2.3:o:netgear:gs810emx_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:xs512em_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:netgear:xs724em_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Netgear Gs810emx Firmware

CVE-2020-26921 — High (CVSS 8.3): Certain NETGEAR devices are affected by authentication bypass. This affects GS110EMX before 1.0.1.7, GS810EMX before…
CVE-2018-21122 — Medium (CVSS 6.5): Certain NETGEAR devices are affected by denial of service. This affects GS110EMX before 1.0.0.9, GS810EMX before…
CVE-2018-21143 — Medium (CVSS 6.5): NETGEAR GS810EMX devices before 1.0.0.5 are affected by disclosure of sensitive information.
CVE-2019-20658 — Medium (CVSS 6.5): Certain NETGEAR devices are affected by disclosure of sensitive information. This affects FS728TLP before 1.0.1.26,…
CVE-2019-20676 — Medium (CVSS 6.0): Certain NETGEAR devices are affected by lack of access control at the function level. This affects FS728TLP before…

All CVEs affecting Netgear Gs810emx Firmware →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-101077 — Critical (CVSS 10.0): A flaw has been found in Netcore NR289-GE 1.4.5102. This impacts the function process_request of the component boa_temp…
CVE-2026-100886 — Critical (CVSS 10.0): A vulnerability was identified in Seetong T8108, T8108P, T8116 and T8232 4.6.1.4-build202604241011. The affected…
CVE-2026-77244 — Critical (CVSS 10.0): MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0,…
CVE-2026-94493 — Critical (CVSS 10.0): A vulnerability was detected in Gigatech PDV5701 1.0.31_240305_112640. This issue affects some unknown processing of…
CVE-2026-83099 — Critical (CVSS 10.0): Vulnerability in the Oracle Forms product of Oracle Fusion Middleware (component: Forms Services, C/S, Charmode).…
CVE-2026-83059 — Critical (CVSS 10.0): Vulnerability in the Oracle Internet Directory product of Oracle Fusion Middleware (component: OID LDAP Server).…

Browse all CWE-287 (Improper Authentication) vulnerabilities →