How severe is CVE-2021-20159?

CVE-2021-20159 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20159 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20159?

CVE-2021-20159 affects Trendnet Tew-827dru Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20159?

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-2021-20159 published?

CVE-2021-20159 was published on 2021-12-30 and last updated on 2026-06-17.

CVE-2021-20159

CVE-2021-20159 is a high-severity vulnerability in Trendnet Tew-827dru 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-78.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.0
EPSS exploit prediction: 3% (87th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Trendnet Tew-827dru Firmware
Published: 2021-12-30
Last modified: 2026-06-17

Description

Trendnet AC2600 TEW-827DRU version 2.08B01 is vulnerable to command injection. The system log functionality of the firmware allows for command injection as root by supplying a malformed parameter.

Frequently asked questions

What is CVE-2021-20159?: Trendnet AC2600 TEW-827DRU version 2.08B01 is vulnerable to command injection. The system log functionality of the firmware allows for command injection as root by supplying a malformed parameter.
How severe is CVE-2021-20159?: CVE-2021-20159 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20159 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20159?: CVE-2021-20159 affects Trendnet Tew-827dru Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20159?: 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-2021-20159 published?: CVE-2021-20159 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:2.08b01:*:*:*:*:*:*:*

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