CVE-2020-8515: Multiple DrayTek Vigor Routers Web Management Page Vulnerability

Vulnerability summary

CVE-2020-8515 is a high (CVSS 10.0) OS Command Injection vulnerability in DrayTek Multiple Vigor Routers. It is known to be exploited: CISA lists it, first on 03-11-2021. EPSS estimates a 99.99% chance of exploitation in the next 30 days, higher than 99.9% of scored vulnerabilities. 2 public exploits are recorded.

Timeline

1. 01-02-2020
   PublishedVulnerability first disclosed.
2. 03-11-2021
   Added to CISA KEVExploitedMultiple DrayTek Vigor Routers Web Management Page Vulnerability
3. 03-05-2022
   CISA remediation dueDeadline passedApply updates per vendor instructions.
4. 21-10-2025
   Last modifiedVulnerability information updated.

Description

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.

• CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.