CVE-2020-8515

CRITICALNVD 9.89.8
EchelonGraph scoreHIGH confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 9.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: CISA Known Exploited Vulnerabilities catalog, EPSS, GitHub Security Advisory, NVD CVSS v3
Exploited in the wild

Also known asEUVD-2020-29381 (ENISA EUVD) · GHSA-4866-p686-25f3 (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at low mission impact
CISA-KEV: ExploitedEPSS PROB: >99.9%CVSS: 9.8Exploit: Public PoCExposed services: Not assessed

The CVE record names the fixed release — apply it.

DrayTek Vigor2960 1.3.1_Beta, Vigor3900 1.4.4_Beta, and Vigor300B 1.3.3_Beta, 1.4.2.1_Beta, and 1.4.4_Beta devices allow remote code execution as root (without authentication) via shell metacharacters to the cgi-bin/mainfunction.cgi URI. This issue has been fixed in Vigor3900/2960/300B v1.5.1.

CVSS v3
9.8
EG Score
9.8CRITICALhigh confidence
EG Risk
99
EG Risk 99/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation100% × 40%
Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Attend at low mission impact; Act at medium or high.
Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: The CVE record names the fixed release. Apply it sooner than your standard update timelines at low mission impact and as soon as possible at medium or high.
EPSS PROB
>99.9%
EPSS %ILE
99th
KEV
⚠ Exploited

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
>99.9% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
CISA KEV and EG-KEV Tier 1 (exploited in the wild)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Act at medium mission impactAttend at low mission impact; Act at medium or high.CISA BOD 26-04: 3 days & forensic triage if the affected system is publicly exposed; 3 days & forensic triage if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Attend at low mission impact; Act at medium or high.

The CVE record names the fixed release. Apply it sooner than your standard update timelines at low mission impact and as soon as possible at medium or high.

Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days & forensic triage if the affected system is publicly exposed; 3 days & forensic triage if it is not.

The score's inputs: In CISA KEV yes (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

CISA required action“Apply updates per vendor instructions.”

Quoted verbatim from CISA's Known Exploited Vulnerabilities catalog. CISA directs it at US federal civilian executive branch agencies under Binding Operational Directive (BOD) 26-04, which replaced BOD 22-01 on 10 June 2026; it is not EchelonGraph's advice. CISA's notes: https://nvd.nist.gov/vuln/detail/CVE-2020-8515

Published

February 1, 2020

Last Modified

November 7, 2025

Advisory Details (3)

Auto-updated Oct 30, 2026
⚠️ Actively exploited (CISA KEV, CISA Vulnrichment). Fix named in the CVE record. Sources: cisa.
CISA🔴 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-2020-8515
Web page

Vigor3900 / Vigor2960 / Vigor300B Router Web Management Page Vulnerability (CVE-2020-8515) | DrayTek

https://www.draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-router-web-management-page-vulnerability-%28cve-2020-8515%29/

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 104× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 982 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 882 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 08:30 UTCEG score recompute
  2. 2026-11-02 08:30 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  3. 2026-11-01 07:11 UTCEG score recompute
  4. 2026-11-01 07:11 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  5. 2026-10-31 05:49 UTCEG score recompute
  6. 2026-10-31 05:48 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  7. 2026-10-30 04:29 UTCEG score recompute
  8. 2026-10-30 04:29 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  9. 2026-10-29 03:10 UTCEG score recompute
  10. 2026-10-29 03:10 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  11. 2026-10-28 01:52 UTCEG score recompute
  12. 2026-10-28 01:51 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  13. 2026-10-27 00:30 UTCEG score recompute
  14. 2026-10-27 00:29 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  15. 2026-10-25 23:09 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  16. 2026-10-25 18:39 UTCEG score recompute
  17. 2026-10-24 21:49 UTCEG score recompute
  18. 2026-10-24 21:49 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  19. 2026-10-23 20:31 UTCEG score recompute
  20. 2026-10-23 20:30 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  21. 2026-10-22 19:12 UTCEG score recompute
  22. 2026-10-22 19:11 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  23. 2026-10-21 17:48 UTCEG score recompute
  24. 2026-10-21 17:48 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  25. 2026-10-20 16:29 UTCEG score recompute
Show 75 more
  1. 2026-10-20 16:29 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  2. 2026-10-19 15:10 UTCEG score recompute
  3. 2026-10-19 15:09 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  4. 2026-10-18 13:49 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  5. 2026-10-18 09:16 UTCEG score recompute
  6. 2026-10-17 12:29 UTCEG score recompute
  7. 2026-10-17 12:29 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  8. 2026-10-16 11:10 UTCEG score recompute
  9. 2026-10-16 11:09 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  10. 2026-10-15 09:49 UTCEG score recompute
  11. 2026-10-15 09:49 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  12. 2026-10-14 08:28 UTCEG score recompute
  13. 2026-10-14 08:28 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  14. 2026-10-13 07:08 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  15. 2026-10-12 19:29 UTCEG score recompute
  16. 2026-10-12 05:48 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  17. 2026-10-12 02:06 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  18. 2026-10-11 22:27 UTCEG score recompute
  19. 2026-10-11 22:27 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  20. 2026-10-11 18:49 UTCEG score recompute
  21. 2026-10-11 18:49 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  22. 2026-10-11 15:10 UTCEG score recompute
  23. 2026-10-11 15:09 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  24. 2026-10-11 11:29 UTCEG score recompute
  25. 2026-10-11 11:29 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  26. 2026-10-11 07:50 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  27. 2026-10-11 04:11 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  28. 2026-10-11 00:30 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  29. 2026-10-10 20:51 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  30. 2026-10-10 17:11 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  31. 2026-10-10 13:32 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  32. 2026-10-10 09:54 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  33. 2026-10-10 06:15 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  34. 2026-10-10 02:37 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  35. 2026-10-09 22:57 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  36. 2026-10-09 19:18 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  37. 2026-10-09 15:39 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  38. 2026-10-09 12:01 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  39. 2026-10-09 08:22 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  40. 2026-10-09 04:43 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  41. 2026-10-09 01:03 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  42. 2026-10-08 21:24 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  43. 2026-10-08 17:45 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  44. 2026-10-08 14:00 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  45. 2026-10-08 10:19 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  46. 2026-10-08 06:40 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  47. 2026-10-08 03:01 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  48. 2026-10-07 23:22 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  49. 2026-10-07 19:43 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  50. 2026-10-07 16:05 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  51. 2026-10-07 12:26 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  52. 2026-10-07 08:45 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  53. 2026-10-07 05:06 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  54. 2026-10-07 01:27 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  55. 2026-10-06 21:48 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  56. 2026-10-06 18:09 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  57. 2026-10-06 14:30 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  58. 2026-10-06 10:51 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  59. 2026-10-06 07:13 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  60. 2026-10-06 03:34 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  61. 2026-10-06 03:33 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  62. 2026-10-06 03:33 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  63. 2026-10-05 23:54 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  64. 2026-10-05 20:16 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  65. 2026-10-05 16:37 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  66. 2026-10-05 12:58 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  67. 2026-10-05 09:19 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  68. 2026-10-05 05:39 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  69. 2026-10-05 02:00 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  70. 2026-10-04 22:21 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  71. 2026-10-04 18:42 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  72. 2026-10-04 15:02 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  73. 2026-10-04 11:23 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  74. 2026-10-04 07:45 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8
  75. 2026-10-04 04:06 UTCGHSA enrichmentGHSA-4866-p686-25f3 · GitHub severity HIGH · GitHub CVSS 9.8

Publicly available exploits

(5 references)

Public exploit code is referenced for this CVE (1 Exploit-DB entry, 3 GitHub PoCs), as is 1 Nuclei detection template. A detection template checks whether a system is affected; it is not necessarily exploit code. Defenders should treat patch urgency accordingly.

  • GitHub PoCdarrenmartyn/CVE-2020-8515
    Published Sep 1, 2021

    Draytek CVE-2020-8515 PoC

    Open source ↗
  • Nucleihttp/cves/2020/CVE-2020-8515.yaml
    Published Jan 28, 2021

    DrayTek - Remote Code Execution

    Open source ↗
  • GitHub PoCtruerandom/nmap_draytek_rce
    Published Mar 31, 2020

    nmap script to detect CVE-2020-8515 on Draytek Devices

    Open source ↗
  • Exploit-DBEDB-48268
    Published Mar 30, 2020

    Multiple DrayTek Products - Pre-authentication Remote Root Code Execution

    Open source ↗
  • GitHub PoCimjdl/CVE-2020-8515-PoC
    Published Mar 30, 2020

    CVE-2020-8515-PoC

    Open source ↗

Frequently asked(6)

What is CVE-2020-8515?
CVE-2020-8515 is a critical-severity vulnerability; its CVE record was published on February 1, 2020. DrayTek Vigor2960 1.3.1_Beta, Vigor3900 1.4.4_Beta, and Vigor300B 1.3.3_Beta, 1.4.2.1_Beta, and 1.4.4_Beta devices allow remote code execution as root (without authentication) via shell metacharacters to the cgi-bin/mainfunction.cgi URI. This issue has been fixed in Vigor3900/2960/300B v1.5.1.
When was the CVE record for CVE-2020-8515 published?
The CVE record for CVE-2020-8515 was published on February 1, 2020. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of November 7, 2025; the record at its source may have been updated since.
Is CVE-2020-8515 actively exploited?
Yes. CISA added CVE-2020-8515 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting DrayTek Multiple Vigor Routers. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. The CVE record names the fixed release. Apply it.
What is the CVSS score of CVE-2020-8515?
CVE-2020-8515 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2020-8515?
CVE-2020-8515 affects DrayTek Multiple Vigor Routers.
How do I remediate CVE-2020-8515?
The CVE record for CVE-2020-8515 names the fix: "This issue has been fixed in Vigor3900/2960/300B v1.5.1."

Dependency Blast Radius

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