NVD / CVE Program· CNA talos

CVE-2021-21819: A code execution vulnerability exists in the Libcli Test Environment functionality of D-LINK DIR-3040 1.13B03.

HighCVSS 7.2 · v3.1—No exploit No fix recorded

Noroxi assessment

Priority: Monitor (action score 29/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 2.8% (FIRST EPSS); higher than 87% of all records.
Anyone who can reach it over the internet can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; 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 · FIRST EPSS

A code execution vulnerability exists in the Libcli Test Environment functionality of D-LINK DIR-3040 1.13B03. A specially crafted network request can lead to arbitrary command execution. An attacker can send a sequence of requests to trigger this vulnerability.

Published: Jul 16, 2021
Updated: Jun 16, 2026
EPSS: 2.8% · 87th percentile
CWE: CWE-78

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 28 / 40 · 7.2 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 1 / 30 · 2.8%

CNA vs NVD score

NVD: 7.2
CNA · talos: 9.1; 1.9 point gap

CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

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

Is your version affected? Check it

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
dlink	dir-3040 firmware	cpe:2.3:o:dlink:dir-3040_firmware
dlink	dir-3040	cpe:2.3:h:dlink:dir-3040

Versions reported by the vendor

Affected version ranges reported by the assigning authority (talos). Independent of NVD's CPE analysis and usually ahead of it.

n/a D-Link
- D-LINK DIR-3040 1.13B03affected

Affected versions

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

dlink dir-3040 firmware1.13b03

Same product

dlink: all records

Other highest-scoring records for the same primary product.

CVE-2022-44832D-Link DIR-3040 device with firmware 120B03 was discovered to contain a command injection vulnerability via the SetTriggerLEDBlink function.
40Plan
CVE-2021-21913An information disclosure vulnerability exists in the WiFi Smart Mesh functionality of D-LINK DIR-3040 1.13B03.
40Plan
CVE-2021-21820A hard-coded password vulnerability exists in the Libcli Test Environment functionality of D-LINK DIR-3040 1.13B03.
40Plan

Published before and after this one in the same product

← EarlierCVE-2021-21817Jul 16, 2021 · An information disclosure vulnerability exists in the Zebra IP Routing Manager functionality of D-LINK DIR-3040 1.13B03.
31Monitor
← EarlierCVE-2021-21818Jul 16, 2021 · A hard-coded password vulnerability exists in the Zebra IP Routing Manager functionality of D-LINK DIR-3040 1.13B03.
31Monitor
Later →CVE-2022-43648Mar 29, 2023 · This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of D-Link DIR-3040 1.20B03 routers.
35Monitor

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

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

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.

No dated events beyond publication.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
Administrator privileges are 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: High
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:H/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 (0)

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

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