NVD / CVE Program· CNA mitre

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

Noroxi assessment

Priority: Now (action score 99/100)

CISA has confirmed exploitation in the wild (Nov 3, 2021). Remediation deadline for US federal agencies: May 3, 2022.
A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
Probability of exploitation in the next 30 days: 99.9% (FIRST EPSS); higher than 99.9% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
According to the record, no fixed version is available yet.
Mentioned 2 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Patch today or shut off access. Until a fix is released, restrict access to the affected component and follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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.

CriticalCVSS 9.8 · v3.1KEVWeaponized No fix recorded

BDU:2021-04387

Published: Feb 1, 2020
Updated: Jun 16, 2026
EPSS: 99.9% · 99th percentile
CWE: CWE-78

Report tools

JSON

Action score

Now

Patch today or shut off access.

CVSS: 39 / 40 · 9.8 / 10
CISA KEV: 30 / 30 · Listed
EPSS: 30 / 30 · 99.9%

CISA SSVC decision

Exploitation: active
Automatable: yes
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Nov 3, 2021. That signals real attacks, not theory.

Remediation deadline for US federal agencies: May 3, 2022.

Get told when this record changes

In CISA KEV: exploitation in the wild confirmed
Weaponized exploit exists
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
draytek	vigor2960 firmware	cpe:2.3:o:draytek:vigor2960_firmware
draytek	vigor2960	cpe:2.3:h:draytek:vigor2960
draytek	vigor300b firmware	cpe:2.3:o:draytek:vigor300b_firmware
draytek	vigor300b	cpe:2.3:h:draytek:vigor300b
draytek	vigor3900 firmware	cpe:2.3:o:draytek:vigor3900_firmware
draytek	vigor3900	cpe:2.3:h:draytek:vigor3900

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

draytek vigor2960 firmware1.3.1
draytek vigor300b firmware1.3.3
draytek vigor300b firmware1.4.2.1
draytek vigor300b firmware1.4.4
draytek vigor3900 firmware1.4.4

Same product

draytek: all records

Other highest-scoring records for the same primary product.

CVE-2021-43118A Remote Command Injection vulnerability exists in DrayTek Vigor 2960 1.5.1.3, DrayTek Vigor 3900 1.5.1.3, and DrayTek Vigor 300B 1.5.1.3 vi
49Plan
CVE-2021-42911A Format String vulnerability exists in DrayTek Vigor 2960 <= 1.5.1.3, DrayTek Vigor 3900 <= 1.5.1.3, and DrayTek Vigor 300B <= 1.5.1.3 in t
40Plan
CVE-2020-19664DrayTek Vigor2960 1.5.1 allows remote command execution via shell metacharacters in a toLogin2FA action to mainfunction.cgi.
37Monitor

Published before and after this one in the same product

Later →CVE-2023-1009Feb 24, 2023 · DrayTek Vigor 2960 Web Management Interface mainfunction.cgi sub_1DF14 path traversal
27Monitor
Later →CVE-2023-24229Mar 15, 2023 · DrayTek Vigor2960 v1.5.1.4 allows an authenticated attacker with network access to the web management interface to inject operating system c
33Monitor
Later →CVE-2023-6265Nov 22, 2023 · DrayTek Vigor2960 mainfunction.cgi dumpSyslog 'option' directory traversal
33Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

Exploit-DB entry ×1
Nuclei detection template ×1
Proof-of-concept repository on GitHub ×3

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Exploit-DB entry	remote	2020-03-30
Nuclei detection template	Nuclei template CVE-2020-8515	—
Proof-of-concept repository on GitHub	stars:14	2020-03-30
Proof-of-concept repository on GitHub	stars:3	2020-03-31
Proof-of-concept repository on GitHub	stars:5	2021-09-01

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

PublishedFeb 1, 2020
First PoCMar 30, 2020+58 d
CISA KEVNov 3, 2021+641 d
TodayNov 2, 2026+2466 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-20-262 · Apr 23, 2020(Uzaktan Erişim Servislerine Yönelik Önlemler)
TR-20-182 · Mar 31, 2020(Draytek Endüstriyel Ürünler Zafiyeti)

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

CVSS vector

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

nvd-primary

Root cause

User input is inserted as text into a shell command. The shell may interpret special characters in the input as part of the command.

The bug in code

The whole CWE-78 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1const host = req.body.host;
2exec("ping -c 1 " + host, onResult);

Fixed

1const host = req.body.host;
2if (!/^[a-z0-9.-]{1,253}$/i.test(host)) return res.sendStatus(400);
3execFile("ping", ["-c", "1", host], onResult);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

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Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

sku11army.blogspot.com/2020/01/draytek-unauthenticated-rce-in-draytek.html

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records