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...

9.8 CriticalIn KEVPublic exploit

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

100.0%Up 92.3 points since Apr 14, 2021

What each source reports

NVD Score used 9.8

Record: CVE-2020-8515
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0: 10.0 HighAV:N/AC:L/Au:N/C:C/I:C/A:C
Weakness: CWE-78
Updated: 2026-11-02

CVE List 9.8

Record: CVE-2020-8515
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-78
Updated: 2026-11-02

EUVDEUVD-2020-29381 9.8

Record: EUVD-2020-29381
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-4866-p686-25f3 9.8

DrayTek Vigor2960 1.3.1_Beta; Vigor3900 1.4.4_Beta; and Vigor300B 1.3.3_Beta, 1.4.2.1_Beta, and 1...

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.

Record: GHSA-4866-p686-25f3
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-74, CWE-78
Updated: 2026-11-02

CISA KEV No score

Multiple DrayTek Vigor Routers Web Management Page Vulnerability

DrayTek Vigor3900, Vigor2960, and Vigor300B routers contain an unspecified vulnerability that allows for remote code execution.

Record: CVE-2020-8515
Weakness: CWE-78
Updated: 2026-11-02

Affected products

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
Exploit-DB	Multiple DrayTek Products - Pre-authentication Remote Root Code Execution	2020-03-30
PoC in GitHub	imjdl/CVE-2020-8515-PoC	2020-03-30
PoC in GitHub	truerandom/nmap_draytek_rce	2020-03-31
PoC in GitHub	darrenmartyn/CVE-2020-8515	2021-09-01
Nuclei	DrayTek - Remote Code Execution

History

History
Recorded	Changed	Sources
Nov 3, 2026	exploitation, exploits
Nov 2, 2026	first indexed	CVE List, EUVD, Exploit-DB, GitHub Advisories, CISA KEV, Nuclei, NVD, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2020-8515 is a critical vulnerability (CVSS 9.8) in Draytek Multiple Vigor Routers, published February 1, 2020. CISA lists it as known to be exploited, since November 3, 2021. EUVD reports exploitation since November 3, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 100.0%, the 99th percentile. No source names a fixed version.