Exploited CVEs / DrayTek / CVE-2020-8515

CVE-2020-8515

Multiple DrayTek Vigor Routers Web Management Page Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2022-05-03 (that deadline has passed); treat that date as the outer bound for your own environment. Check the vendor security advisory for the fix.

Risk summary

CriticalCISA KEV

9.8

CVSS base

100%

EPSS exploit probability

Critical

Severity

2021-11-03

Added to KEV

2022-05-03 (past due)

CISA due date

Actively exploited DrayTek Multiple Vigor Routers vulnerability, Critical severity, CVSS 9.8. Added to the CISA KEV catalog 2021-11-03.

Senserva AI read on CVE-2020-8515 CISA required action Official fix for CVE-2020-8515 Admin questions

Senserva AI Opinion for CVE-2020-8515

DrayTek Vigor3900, Vigor2960, and Vigor300B routers carry a remote code execution flaw with a 100 percent EPSS score, and botnets mass-exploited it against internet-facing devices. Attackers who own the router own the traffic: DNS hijacking, credential capture, and lateral staging all follow. These models are common in small branch offices where nobody watches the edge device.

Do this: Patch or replace affected DrayTek Vigor routers today and check their DNS and admin settings for unauthorized changes.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2020-8515

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I run IT security. Facts for CVE-2020-8515, an actively exploited vulnerability (source: https://senserva.com/cve/CVE-2020-8515.html, data from CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2020-8515: Multiple DrayTek Vigor Routers Web Management Page Vulnerability
- Affected: DrayTek Multiple Vigor Routers
- Severity: Critical, CVSS 9.8; EPSS 30-day exploitation probability 100%
- Added to CISA KEV: 2021-11-03; federal remediation due 2022-05-03
- Ransomware-linked: no
- CISA required action: Apply updates per vendor instructions.
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) The fastest safe path to remediation. 4) How to check whether my environment is exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Patch now

Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.

No vendor fix is mapped yet. This page refreshes daily and will name the patch the day one is published.

Do this now: Federal remediation deadline 2022-05-03; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated August 14, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2020-8515

Published: 2021-11-03
Last revised: 2021-11-03
Changes tracked: 1

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

Senserva Watchevery change we have recorded for this one

What changed, and when

2021-11-03 added to the CISA KEV catalog by CISA
2026-07-17 CVSS 0.0 to 9.8; EPSS first scored at 100.0%

Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.

CISA required action

Federal (BOD 22-01) remediation due date: 2022-05-03 (past due).

Apply updates per vendor instructions.

Official fix for CVE-2020-8515

Check the vendor's security advisory channel for the patched Multiple Vigor Routers versions and workarounds.

CISA KEV entry

Common questions about CVE-2020-8515

Is CVE-2020-8515 actively exploited?

Yes. CVE-2020-8515 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 100%.

What is the CISA deadline and required action for CVE-2020-8515?

CISA set the federal (BOD 22-01) remediation due date at 2022-05-03, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply updates per vendor instructions.

What fixes CVE-2020-8515?

Check the vendor's security advisory for the patched Multiple Vigor Routers versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2020-8515?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2020-8515's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).

Scope and sources

More exploited DrayTek CVEs: CVE-2024-12987 CVE-2020-15415 CVE-2021-20123 CVE-2021-20124
All DrayTek exploited CVEs on one page: DrayTek vulnerabilities actively exploited.
Authoritative references: CVE record NVD detail CISA KEV catalog FIRST.org EPSS

Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.