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

Exploited in the wild Critical 9.8 Published 1 Feb 2020 Updated 21 Oct 2025

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

Exploited in the wild: Since 3 Nov 2021
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

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

Which versions are affected by CVE-2020-8515?

It affects 3 products.

Products include 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.

Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.

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: 1 Exploit-DB entry, 1 Nuclei template and 3 proofs of concept on GitHub.

Sources

Also known as GHSA-4866-p686-25f3.