CVE-2021-44827

HIGHNVD 8.88.9▲
EchelonGraph scoreHIGH confidence

Score elevated to 8.9 because EPSS predicts 54% probability of exploitation within the next 30 days (top 1.1% of all CVEs). NVD baseline CVSS 8.8 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction ≥85%
Sources: epss, ghsa, nvd
Elevated
8.8
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 54%
CISA-KEV: Not listedEPSS: 54%CVSS: 8.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

There is remote authenticated OS command injection on TP-Link Archer C20i 0.9.1 3.2 v003a.0 Build 170221 Rel.55462n devices vie the X_TP_ExternalIPv6Address HTTP parameter, allowing a remote attacker to run arbitrary commands on the router with root privileges.

CVSS v3
8.8
EG Score
8.9(high)
EG Risk
66(Track)
EG Risk 66/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity89% × 45%
Exploitation54% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
98.9%
KEV
Not listed

Published

March 4, 2022

Last Modified

November 21, 2024

References (6)

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 32× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-24 14:15 UTCEPSS rescore
  2. 2026-07-23 14:16 UTCEPSS rescore
  3. 2026-07-23 02:05 UTCEG score recompute▲ 0.10
  4. 2026-07-22 22:52 UTCEG score recompute
  5. 2026-07-22 14:06 UTCEPSS rescore
  6. 2026-07-20 17:05 UTCEPSS rescore
  7. 2026-07-19 02:27 UTCEPSS rescore
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  10. 2026-07-15 16:55 UTCEPSS rescore
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  12. 2026-07-13 22:27 UTCEPSS rescore
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  25. 2026-06-30 23:20 UTCEPSS rescore
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  1. 2026-06-30 23:20 UTCEPSS rescore
  2. 2026-06-28 04:54 UTCEPSS rescore
  3. 2026-06-28 04:54 UTCEPSS rescore
  4. 2026-06-27 03:06 UTCEPSS rescore
  5. 2026-06-27 03:06 UTCEPSS rescore
  6. 2026-06-25 13:48 UTCEPSS rescore
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  8. 2026-06-24 14:03 UTCEPSS rescore
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  10. 2026-06-23 21:31 UTCEPSS rescore
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  12. 2026-06-22 14:24 UTCEPSS rescore
  13. 2026-06-21 01:58 UTCEPSS rescore
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  15. 2026-06-18 17:51 UTCEPSS rescore
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  22. 2026-06-15 17:46 UTCEPSS rescore
  23. 2026-06-12 23:10 UTCEPSS rescore
  24. 2026-06-11 13:58 UTCEPSS rescore
  25. 2026-06-11 13:58 UTCEPSS rescore
  26. 2026-06-10 22:16 UTCEPSS rescore
  27. 2026-06-10 22:16 UTCEPSS rescore
  28. 2026-06-10 13:20 UTCEPSS rescore
  29. 2026-06-08 14:15 UTCEPSS rescore
  30. 2026-06-08 14:15 UTCEPSS rescore
  31. 2026-06-06 13:46 UTCEPSS rescore
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  36. 2026-06-04 13:10 UTCEPSS rescore
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  38. 2026-06-02 20:11 UTCEPSS rescore
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  40. 2026-05-31 22:29 UTCEPSS rescore
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  42. 2026-05-31 00:15 UTCEPSS rescore
  43. 2026-05-31 00:15 UTCEPSS rescore
  44. 2026-05-29 13:42 UTCEPSS rescore
  45. 2026-05-28 13:43 UTCEPSS rescore
  46. 2026-05-28 13:43 UTCEPSS rescore
  47. 2026-05-27 13:39 UTCEPSS rescore
  48. 2026-05-27 13:39 UTCEPSS rescore
  49. 2026-05-26 07:17 UTCEPSS rescore
  50. 2026-05-26 07:17 UTCEPSS rescore
  51. 2026-05-26 07:17 UTCEPSS rescore
  52. 2026-05-26 02:09 UTCEG score recompute
  53. 2026-05-26 02:09 UTCGHSA enrichment
  54. 2026-05-24 20:12 UTCOSV refresh

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCfull-disclosure/CVE-2021-44827
    First seen Dec 13, 2021

    A PoC for CVE-2021-44827 - authenticated remote code execution in Tp-link Archer C20i

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-44827?
CVE-2021-44827 is a high vulnerability published on March 4, 2022. There is remote authenticated OS command injection on TP-Link Archer C20i 0.9.1 3.2 v003a.0 Build 170221 Rel.55462n devices vie the XTPExternalIPv6Address HTTP parameter, allowing a remote attacker to run arbitrary commands on the router with root privileges.
When was CVE-2021-44827 disclosed?
CVE-2021-44827 was first published in the National Vulnerability Database on March 4, 2022, 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-2021-44827 actively exploited?
CVE-2021-44827 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 98.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-44827?
CVE-2021-44827 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.9.
How do I remediate CVE-2021-44827?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-44827, 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

Explore the affected products and dependency analysis for CVE-2021-44827

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