What is CVE-2020-8515?

CVE-2020-8515 is a critical-severity vulnerability in Draytek Vigor2960, classified under OS Command Injection. CVSS score: 9.8/10. Published 2020-02-01.

How severe is CVE-2020-8515?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2020-8515 known to be exploited?

Yes. CVE-2020-8515 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 44 public proof-of-concept repositories are indexed.

RCE in Draytek Vigor2960

CVE-2020-8515

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.

Vulnerability class: Command Injection (OS Command Injection)

Published 2020-02-01 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 1.000 (100.0th percentile), scored 2026-09-25.

Very high probability of exploitation in the next 30 days — among the top 0.1% most-likely-to-be-exploited CVEs. 100th percentile — 100.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 1.000 · newest: 1.000 · change: 0.000

Affected products

Draytek Vigor2960
Draytek Vigor2960 Firmware — versions 1.3.1
Draytek Vigor300b
Draytek Vigor300b Firmware — versions 1.3.3, 1.4.2.1, 1.4.4
Draytek Vigor3900
Draytek Vigor3900 Firmware — versions 1.4.4

Weakness classification (CWE)

CWE-78 — OS Command Injection

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2021-11-03. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2022-05-03.

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

sku11army.blogspot.com/2020/01/draytek-unauthenticated-rce-in-draytek.html (Permissions Required, Third Party Advisory)
www.draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-route… (Vendor Advisory)
packetstormsecurity.com/files/156979/DrayTek-Vigor2960-Vigor3900-Vigor300B-Remo… (Exploit, VDB Entry, Third Party Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2020-8515?: CVE-2020-8515 is a critical-severity vulnerability in Draytek Vigor2960, classified under OS Command Injection. CVSS score: 9.8/10. Published 2020-02-01.
How severe is CVE-2020-8515?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2020-8515 known to be exploited?: Yes. CVE-2020-8515 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 44 public proof-of-concept repositories are indexed.