CVE-2020-3577

HIGHNVD 7.47.4—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.4 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 64% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.4EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.4Exploit: None knownExposed: 0

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

A vulnerability in the ingress packet processing path of Cisco Firepower Threat Defense (FTD) Software for interfaces that are configured either as Inline Pair or in Passive mode could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient validation when Ethernet frames are processed. An attacker could exploit this vulnerability by sending malicious Ethernet frames through an affected device. A successful exploit could allow the attacker do either of the following: Fill the /ngfw partition on the device: A full /ngfw partition could result in administrators being unable to log in to the device (including logging in through the console port) or the device being unable to boot up correctly. Note: Manual intervention is required to recover from this situation. Customers are advised to contact the Cisco Technical Assistance Center (TAC) to help recover a device in this condition. Cause a process crash: The process crash would cause the device to reload. No manual intervention is necessary to recover the device after the reload.

CVSS v3
7.4
EG Score
7.4(medium)
EG Risk
33(Track)
EG Risk 33/100SSVC: 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
Severity74% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
36%
KEV
Not listed

Published

October 21, 2020

Last Modified

August 11, 2026

Advisory Details (1)

Auto-updated Aug 11, 2026
No patch confirmed yet.
generic

Cisco Firepower Threat Defense Software Inline Pair/Passive Mode Denial of Service Vulnerability

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-inline-dos-nXqUyEqM

Vendor Advisories for CVE-2020-3577(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 29× 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 118 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2020-3577?
CVE-2020-3577 is a high vulnerability published on October 21, 2020. A vulnerability in the ingress packet processing path of Cisco Firepower Threat Defense (FTD) Software for interfaces that are configured either as Inline Pair or in Passive mode could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. The vulnerability is due…
When was CVE-2020-3577 disclosed?
CVE-2020-3577 was first published in the National Vulnerability Database on October 21, 2020, with the most recent update on August 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-3577 actively exploited?
CVE-2020-3577 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 63.6% of all scored CVEs.
What is the CVSS score of CVE-2020-3577?
CVE-2020-3577 has a CVSS v3 base score of 7.4 (NVD).
How do I remediate CVE-2020-3577?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-3577, 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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