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

> Remote attackers can execute arbitrary commands as root on DrayTek routers without authentication via shell metacharacters in the mainfunction.cgi URI.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 3 Nov 2021 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Feb 2020
- **Updated:** 21 Oct 2025
- **Also known as:** GHSA-4866-p686-25f3

## What is CVE-2020-8515?

CVE-2020-8515 is a critical command injection vulnerability in n/a, published on 1 Feb 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2020-8515?

It affects 3 products.


Products: Draytek Vigor2960 Firmware, Draytek Vigor300b Firmware, Draytek Vigor3900 Firmware.

## How do I fix CVE-2020-8515?

No fix has been published for CVE-2020-8515 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 3 May 2022.

## Is CVE-2020-8515 being exploited?

Yes. Attackers have exploited CVE-2020-8515 in the wild since at least 3 Nov 2021.

Public exploit code:

- CVE-2020-8515-PoC (github_poc): https://github.com/imjdl/CVE-2020-8515-PoC
- Draytek CVE-2020-8515 PoC (github_poc): https://github.com/darrenmartyn/CVE-2020-8515
- nmap script to detect CVE-2020-8515 on Draytek Devices (github_poc): https://github.com/truerandom/nmap_draytek_rce
- Multiple DrayTek Products - Pre-authentication Remote Root Code Execution (exploitdb)
- DrayTek - Remote Code Execution (nuclei): http/cves/2020/CVE-2020-8515.yaml

## Other vulnerabilities in n/a

- [CVE-2020-15415](https://insights.sbomify.com/CVE-2020-15415/): DrayTek Multiple Vigor Routers OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2024-12987](https://insights.sbomify.com/CVE-2024-12987/): DrayTek Vigor Routers OS Command Injection (medium 6.9, exploited in the wild)
- [CVE-2021-42911](https://insights.sbomify.com/CVE-2021-42911/): Other in n/a (critical 9.8)
- [CVE-2021-43118](https://insights.sbomify.com/CVE-2021-43118/): Command injection in n/a (critical 9.8)
- [CVE-2020-14472](https://insights.sbomify.com/CVE-2020-14472/): Command injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-8515 and fix it if it is affected.

What it is: CVE-2020-8515 is a critical command injection vulnerability in n/a, published on 1 Feb 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2020-8515 in the wild since at least 3 Nov 2021.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2020-8515/ (Markdown: https://insights.sbomify.com/CVE-2020-8515/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-8515
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-8515
- OSV: https://osv.dev/vulnerability/CVE-2020-8515

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-8515/
Summaries are generated and may contain mistakes; the official description above is the record.