CVE-2021-40655

HIGHNVD 7.59.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2024-05-16), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 7.5 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 4 sources updated this weekExploited in the wild
7.5
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 87%CVSS: 7.5Exploit: NoneExposed: 0

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

An informtion disclosure issue exists in D-LINK-DIR-605 B2 Firmware Version : 2.01MT. An attacker can obtain a user name and password by forging a post request to the / getcfg.php page

CVSS v3
7.5
EG Score
9.0(high)
EG Risk
81(Attend)
EG Risk 81/100SSVC: Attend

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
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS
99.7%
KEV
⚠ Exploited

Published

September 24, 2021

Last Modified

November 10, 2025

Advisory Details (3)

Auto-updated Jun 5, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-40655
generic

Security Bulletin | D-Link

https://www.dlink.com/en/security-bulletin/
generic

GitHub - Ilovewomen/D-LINK-DIR-605 · GitHub

https://github.com/Ilovewomen/D-LINK-DIR-605/

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 38× in last 7d / 211× 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.

Showing the most recent 100 of 402 total refreshes for this CVE.

  1. 2026-07-24 14:15 UTCEPSS rescore
  2. 2026-07-23 02:04 UTCEG score recompute
  3. 2026-07-22 22:34 UTCEG score recompute
  4. 2026-07-22 22:34 UTCGHSA enrichment
  5. 2026-07-22 19:40 UTCCISA KEV update
  6. 2026-07-22 18:48 UTCGHSA enrichment
  7. 2026-07-22 15:03 UTCEG score recompute
  8. 2026-07-22 15:03 UTCGHSA enrichment
  9. 2026-07-22 14:06 UTCEPSS rescore
  10. 2026-07-22 11:16 UTCGHSA enrichment
  11. 2026-07-22 07:31 UTCGHSA enrichment
  12. 2026-07-22 03:46 UTCGHSA enrichment
  13. 2026-07-21 23:58 UTCGHSA enrichment
  14. 2026-07-21 18:26 UTCGHSA enrichment
  15. 2026-07-21 14:40 UTCGHSA enrichment
  16. 2026-07-21 14:37 UTCCISA KEV update
  17. 2026-07-21 10:55 UTCGHSA enrichment
  18. 2026-07-21 07:10 UTCGHSA enrichment
  19. 2026-07-21 03:25 UTCGHSA enrichment
  20. 2026-07-20 23:39 UTCGHSA enrichment
  21. 2026-07-20 19:54 UTCEG score recompute
  22. 2026-07-20 19:54 UTCGHSA enrichment
  23. 2026-07-20 17:05 UTCEPSS rescore
  24. 2026-07-20 16:09 UTCGHSA enrichment
  25. 2026-07-20 12:24 UTCGHSA enrichment
Show 75 more
  1. 2026-07-20 08:39 UTCGHSA enrichment
  2. 2026-07-20 04:54 UTCGHSA enrichment
  3. 2026-07-19 21:24 UTCGHSA enrichment
  4. 2026-07-19 17:39 UTCGHSA enrichment
  5. 2026-07-19 13:54 UTCGHSA enrichment
  6. 2026-07-19 10:10 UTCGHSA enrichment
  7. 2026-07-19 06:25 UTCGHSA enrichment
  8. 2026-07-19 02:40 UTCGHSA enrichment
  9. 2026-07-18 22:55 UTCGHSA enrichment
  10. 2026-07-18 19:10 UTCGHSA enrichment
  11. 2026-07-18 15:24 UTCGHSA enrichment
  12. 2026-07-18 11:38 UTCGHSA enrichment
  13. 2026-07-18 07:53 UTCGHSA enrichment
  14. 2026-07-18 04:08 UTCGHSA enrichment
  15. 2026-07-18 00:23 UTCGHSA enrichment
  16. 2026-07-17 20:38 UTCGHSA enrichment
  17. 2026-07-17 16:52 UTCGHSA enrichment
  18. 2026-07-17 13:06 UTCGHSA enrichment
  19. 2026-07-17 09:21 UTCEG score recompute
  20. 2026-07-17 09:21 UTCGHSA enrichment
  21. 2026-07-17 05:36 UTCGHSA enrichment
  22. 2026-07-17 01:51 UTCGHSA enrichment
  23. 2026-07-16 22:06 UTCGHSA enrichment
  24. 2026-07-16 18:21 UTCGHSA enrichment
  25. 2026-07-16 17:04 UTCCISA KEV update
  26. 2026-07-16 14:34 UTCGHSA enrichment
  27. 2026-07-16 10:48 UTCGHSA enrichment
  28. 2026-07-16 07:03 UTCGHSA enrichment
  29. 2026-07-16 03:19 UTCGHSA enrichment
  30. 2026-07-15 23:34 UTCGHSA enrichment
  31. 2026-07-15 19:49 UTCGHSA enrichment
  32. 2026-07-15 16:55 UTCEPSS rescore
  33. 2026-07-15 16:55 UTCEPSS rescore
  34. 2026-07-15 16:49 UTCCISA KEV update
  35. 2026-07-15 16:03 UTCGHSA enrichment
  36. 2026-07-15 15:04 UTCCISA KEV update
  37. 2026-07-15 12:17 UTCGHSA enrichment
  38. 2026-07-15 08:32 UTCGHSA enrichment
  39. 2026-07-15 04:47 UTCGHSA enrichment
  40. 2026-07-15 01:02 UTCGHSA enrichment
  41. 2026-07-14 21:17 UTCGHSA enrichment
  42. 2026-07-14 18:05 UTCCISA KEV update
  43. 2026-07-14 17:32 UTCGHSA enrichment
  44. 2026-07-14 13:47 UTCGHSA enrichment
  45. 2026-07-14 10:01 UTCGHSA enrichment
  46. 2026-07-14 06:17 UTCGHSA enrichment
  47. 2026-07-14 02:31 UTCGHSA enrichment
  48. 2026-07-13 22:46 UTCGHSA enrichment
  49. 2026-07-13 22:27 UTCEPSS rescore
  50. 2026-07-13 22:27 UTCEPSS rescore
  51. 2026-07-13 19:01 UTCGHSA enrichment
  52. 2026-07-13 17:07 UTCCISA KEV update
  53. 2026-07-13 15:15 UTCGHSA enrichment
  54. 2026-07-13 11:30 UTCGHSA enrichment
  55. 2026-07-13 07:45 UTCGHSA enrichment
  56. 2026-07-13 06:11 UTCEPSS rescore
  57. 2026-07-13 06:11 UTCEPSS rescore
  58. 2026-07-13 04:00 UTCGHSA enrichment
  59. 2026-07-13 00:15 UTCGHSA enrichment
  60. 2026-07-12 20:30 UTCGHSA enrichment
  61. 2026-07-12 16:44 UTCGHSA enrichment
  62. 2026-07-12 12:59 UTCGHSA enrichment
  63. 2026-07-12 09:14 UTCGHSA enrichment
  64. 2026-07-12 05:29 UTCGHSA enrichment
  65. 2026-07-12 01:43 UTCGHSA enrichment
  66. 2026-07-11 21:59 UTCGHSA enrichment
  67. 2026-07-11 18:14 UTCGHSA enrichment
  68. 2026-07-11 14:29 UTCGHSA enrichment
  69. 2026-07-11 10:44 UTCGHSA enrichment
  70. 2026-07-11 08:25 UTCEPSS rescore
  71. 2026-07-11 08:25 UTCEPSS rescore
  72. 2026-07-11 06:59 UTCGHSA enrichment
  73. 2026-07-11 03:14 UTCGHSA enrichment
  74. 2026-07-10 23:28 UTCGHSA enrichment
  75. 2026-07-10 19:43 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-2021-40655.yaml
    First seen Jan 1, 2021

    D-Link DIR-605 - Information Disclosure

    Open source ↗

Related CVEs(same CWE)

Frequently asked(6)

What is CVE-2021-40655?
CVE-2021-40655 is a high vulnerability published on September 24, 2021. An informtion disclosure issue exists in D-LINK-DIR-605 B2 Firmware Version : 2.01MT. An attacker can obtain a user name and password by forging a post request to the / getcfg.php page
When was CVE-2021-40655 disclosed?
CVE-2021-40655 was first published in the National Vulnerability Database on September 24, 2021, with the most recent update on November 10, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-40655 actively exploited?
Yes. CISA added CVE-2021-40655 to the Known Exploited Vulnerabilities catalog on May 16, 2024, affecting D-Link DIR-605 Router. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-40655?
CVE-2021-40655 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2021-40655?
CVE-2021-40655 affects D-Link DIR-605 Router. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2021-40655?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-40655, 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-2021-40655

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