How severe is CVE-2021-20157?

CVE-2021-20157 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-20157 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-2021-20157?

CVE-2021-20157 affects Trendnet Tew-827dru Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20157?

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-2021-20157 published?

CVE-2021-20157 was published on 2021-12-30 and last updated on 2026-06-17.

CVE-2021-20157

CVE-2021-20157 is a high-severity vulnerability in Trendnet Tew-827dru Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 7.8
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Trendnet Tew-827dru Firmware
Published: 2021-12-30
Last modified: 2026-06-17

Description

It is possible for an unauthenticated, malicious user to force the device to reboot due to a hidden administrative command.

Frequently asked questions

What is CVE-2021-20157?: It is possible for an unauthenticated, malicious user to force the device to reboot due to a hidden administrative command.
How severe is CVE-2021-20157?: CVE-2021-20157 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-20157 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-2021-20157?: CVE-2021-20157 affects Trendnet Tew-827dru Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20157?: 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-2021-20157 published?: CVE-2021-20157 was published on 2021-12-30 and last updated on 2026-06-17.

References

https://www.tenable.com/security/research/tra-2021-54

Affected products (1)

cpe:2.3:o:trendnet:tew-827dru_firmware:-:*:*:*:*:*:*:*

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