CVE-2020-8515

KEVMultiple DrayTek Vigor Routers Web Management Page Vulnerability

Description

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

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 3.1 vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

PublishedFeb 1, 2020

Last modifiedJun 17, 2026

Added to KEVNov 3, 2021

Remediation dueMay 3, 2022

References

packetstormsecurity.com/files/156979/DrayTek-Vigor2960-Vigor3900-Vigor300B-Remote-Command-Execution.htmlExploitThird Party Advisory
sku11army.blogspot.com/2020/01/draytek-unauthenticated-rce-in-draytek.htmlPermissions RequiredThird Party Advisory
draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-router-web-management-page-vulnerability-%28cve-2020-8515%29/Vendor Advisory
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-8515US Government Resource

0 recent articles mention this CVE

Risk assessment · Critical

Actively exploited. Patch immediately.

Exploitation: Confirmed in the wild (CISA KEV)
Federal remediation deadline: Overdue by 1638 days
CVSS: 9.8 CRITICAL
EPSS (30-day exploit probability): 100.0% · top 1% of all CVEs
Weakness: CWE-78
Attack vector: Network, remotely reachable
Preconditions: No privileges and no user interaction

Recommended actions

1.Apply updates per vendor instructions.
2.Treat as emergency change: patch or isolate internet-facing instances first.
3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.

Assessment is derived automatically from the live signals above; verify against your own asset inventory.