CVE-2021-20731

HIGHNVD 8.88.8—

8.8

WSR-1166DHP3 firmware Ver.1.16 and prior and WSR-1166DHP4 firmware Ver.1.02 and prior allow an attacker to execute arbitrary OS commands with root privileges via unspecified vectors.

CVSS v3: 8.8
EG Score: 8.8(medium)
EPSS: 56.0%
KEV: Not listed

Published

June 9, 2021

Last Modified

November 21, 2024

References (4)

vultures@jpcerthttps://jvn.jp/en/vu/JVNVU92862829/index.html
vultures@jpcerthttps://www.buffalo.jp/news/detail/20210531-01.html
af854a3a-2127-422b-91ae-364da2661108https://jvn.jp/en/vu/JVNVU92862829/index.html
af854a3a-2127-422b-91ae-364da2661108https://www.buffalo.jp/news/detail/20210531-01.html

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-78OS Command Injection

Data Freshness Timeline

(refreshed 14× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-05 22:45 UTCepss_batch
2026-06-05 22:45 UTCepss_batch
2026-06-05 06:09 UTCepss_batch
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2026-06-04 13:10 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
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2026-06-01 13:50 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
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2026-05-29 13:42 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 15:17 UTCEG score recompute
2026-05-26 15:17 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2021-20731?

CVE-2021-20731 is a high vulnerability published on June 9, 2021. WSR-1166DHP3 firmware Ver.1.16 and prior and WSR-1166DHP4 firmware Ver.1.02 and prior allow an attacker to execute arbitrary OS commands with root privileges via unspecified vectors.

When was CVE-2021-20731 disclosed?

CVE-2021-20731 was first published in the National Vulnerability Database on June 9, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-20731 actively exploited?

CVE-2021-20731 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 56.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-20731?

CVE-2021-20731 has a CVSS v3 base score of 8.8 (NVD).

How do I remediate CVE-2021-20731?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-20731, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2021-20731

📅 Published

🔄 Last Modified

🔗 References (4)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-20731?

🔗 Related CVEs(same CWE)

Same CWE

Published

Last Modified

References (4)

Frequently asked(5)

Related CVEs(same CWE)