CVE-2021-36765
In CODESYS EtherNetIP before 4.1.0.0, specific EtherNet/IP requests may cause a null pointer...
In CODESYS EtherNetIP before 4.1.0.0, specific EtherNet/IP requests may cause a null pointer dereference in the downloaded vulnerable EtherNet/IP stack that is executed by the CODESYS Control runtime system.
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
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
In CODESYS EtherNetIP before 4.1.0.0, specific EtherNet/IP requests may cause a null pointer dereference in the downloaded vulnerable EtherNet/IP stack that is executed by the CODESYS Control runtime system.
- Record
CVE-2021-36765- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-476
- Updated
- 2026-11-02
CVE List No score
In CODESYS EtherNetIP before 4.1.0.0, specific EtherNet/IP requests may cause a null pointer dereference in the downloaded vulnerable EtherNet/IP stack that is executed by the CODESYS Control runtime system.
- Record
CVE-2021-36765- Updated
- 2026-11-02
EUVDEUVD-2021-23353 No score
In CODESYS EtherNetIP before 4.1.0.0, specific EtherNet/IP requests may cause a null pointer dereference in the downloaded vulnerable EtherNet/IP stack that is executed by the CODESYS Control runtime system.
- Record
EUVD-2021-23353- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-3mpj-h64q-x7gf No score
In CODESYS EtherNetIP before 4.1.0.0, specific EtherNet/IP requests may cause a null pointer...
In CODESYS EtherNetIP before 4.1.0.0, specific EtherNet/IP requests may cause a null pointer dereference in the downloaded vulnerable EtherNet/IP stack that is executed by the CODESYS Control runtime system.
- Record
GHSA-3mpj-h64q-x7gf- Weakness
- CWE-476
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-36765 is a high vulnerability (CVSS 7.5) in Codesys Ethernetip, published August 4, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.99%, the 62nd percentile. No source names a fixed version.