CVE-2021-21820
A hard-coded password vulnerability exists in the Libcli Test Environment functionality of D-LINK...
A hard-coded password vulnerability exists in the Libcli Test Environment functionality of D-LINK DIR-3040 1.13B03. A specially crafted network request can lead to code execution. An attacker can send a sequence of requests to trigger this vulnerability.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
A hard-coded password vulnerability exists in the Libcli Test Environment functionality of D-LINK DIR-3040 1.13B03. A specially crafted network request can lead to code execution. An attacker can send a sequence of requests to trigger this vulnerability.
- Record
CVE-2021-21820- CVSS 3.0
- 10.0 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-798
- Updated
- 2026-11-02
EUVDEUVD-2021-8991
A hard-coded password vulnerability exists in the Libcli Test Environment functionality of D-LINK DIR-3040 1.13B03. A specially crafted network request can lead to code execution. An attacker can send a sequence of requests to trigger this vulnerability.
- Record
EUVD-2021-8991- CVSS 3.0
- 10.0 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-gmq9-r2m4-2qvg
A hard-coded password vulnerability exists in the Libcli Test Environment functionality of D-LINK...
A hard-coded password vulnerability exists in the Libcli Test Environment functionality of D-LINK DIR-3040 1.13B03. A specially crafted network request can lead to code execution. An attacker can send a sequence of requests to trigger this vulnerability.
- Record
GHSA-gmq9-r2m4-2qvg- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-798
- Updated
- 2026-11-02
NVD
A hard-coded password vulnerability exists in the Libcli Test Environment functionality of D-LINK DIR-3040 1.13B03. A specially crafted network request can lead to code execution. An attacker can send a sequence of requests to trigger this vulnerability.
- Record
CVE-2021-21820- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.0
- 10.0 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-798
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-21820 is a critical vulnerability (CVSS 10.0) in Dlink Dir-3040 Firmware, published July 16, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.96%, the 87th percentile. No source names a fixed version.