CVE-2021-42887

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-06-04. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 43%CVSS: 9.8Exploit: NoneExposed: 0

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

In TOTOLINK EX1200T V4.1.2cu.5215, an attacker can bypass login by sending a specific request through formLoginAuth.htm.

CVSS v3
9.8
EG Score
9.8(medium)
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
Severity98% × 45%
Exploitation43% × 40%
Automatability30% × 15%
Action: Watch closely — could escalate to Attend.
EPSS
98.6%
KEV
Not listed

Published

June 3, 2022

Last Modified

November 21, 2024

Advisory Details (1)

Auto-updated Jul 2, 2026
No patch confirmed yet.
generic

vuln/totolink_ex1200t_login_bypass.md at main · p1Kk/vuln · GitHub

https://github.com/p1Kk/vuln/blob/main/totolink_ex1200t_login_bypass.md

Data Freshness Timeline

(refreshed 9× in last 7d / 40× 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 02:04 UTCEG score recompute
  4. 2026-07-22 22:51 UTCEG score recompute
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  1. 2026-07-06 16:25 UTCEPSS rescore
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  5. 2026-07-02 16:57 UTCEPSS rescore
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  18. 2026-06-22 14:24 UTCEPSS rescore
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  23. 2026-06-18 17:51 UTCEPSS rescore
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  36. 2026-06-10 22:16 UTCEPSS rescore
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  40. 2026-06-06 13:46 UTCEPSS rescore
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  43. 2026-06-05 06:09 UTCEPSS rescore
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  47. 2026-06-02 20:11 UTCEPSS rescore
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  49. 2026-06-01 13:50 UTCEPSS rescore
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  51. 2026-05-31 22:29 UTCEPSS rescore
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  53. 2026-05-31 00:15 UTCEPSS rescore
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  55. 2026-05-29 13:42 UTCEPSS rescore
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  58. 2026-05-27 13:39 UTCEPSS rescore
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  60. 2026-05-26 13:42 UTCEPSS rescore
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  62. 2026-05-26 07:17 UTCEPSS rescore
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  64. 2026-05-26 07:17 UTCEPSS rescore
  65. 2026-05-25 21:06 UTCEG score recompute
  66. 2026-05-25 21:06 UTCGHSA enrichment

Publicly available exploits

(1 reference)

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

  • Nucleihttp/cves/2021/CVE-2021-42887.yaml
    First seen Jan 1, 2021

    TOTOLINK EX1200T 4.1.2cu.5215 - Authentication Bypass

    Open source ↗

Frequently asked(5)

What is CVE-2021-42887?
CVE-2021-42887 is a critical vulnerability published on June 3, 2022. In TOTOLINK EX1200T V4.1.2cu.5215, an attacker can bypass login by sending a specific request through formLoginAuth.htm.
When was CVE-2021-42887 disclosed?
CVE-2021-42887 was first published in the National Vulnerability Database on June 3, 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-2021-42887 actively exploited?
CVE-2021-42887 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 98.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-42887?
CVE-2021-42887 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2021-42887?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-42887, 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.

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