Is CVE-2021-40342 actively exploited?

No active exploitation of CVE-2021-40342 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-40342 be exploited remotely?

Yes. CVE-2021-40342 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-40342?

CVE-2021-40342 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2021-40342

CRITICAL

CVE-2021-40342

CWE-798Published: January 5, 2023· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

In the DES implementation, the affected product versions use a default key for encryption. Successful exploitation allows an attacker to obtain sensitive information and gain access to the network elements that are managed by the affected products versions.

This issue affects

* FOXMAN-UN product: FOXMAN-UN R16A, FOXMAN-UN R15B, FOXMAN-UN R15A, FOXMAN-UN R14B, FOXMAN-UN R14A, FOXMAN-UN R11B, FOXMAN-UN R11A, FOXMAN-UN R10C, FOXMAN-UN R9C;

* UNEM product: UNEM R16A, UNEM R15B, UNEM R15A, UNEM R14B, UNEM R14A, UNEM R11B, UNEM R11A, UNEM R10C, UNEM R9C.

List of CPEs:

* cpe:2.3:a:hitachienergy:foxman-un:R16A:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:foxman-un:R15B:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:foxman-un:R15A:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:foxman-un:R14B:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:foxman-un:R14A:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:foxman-un:R11B:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:foxman-un:R11A:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:foxman-un:R10C:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:foxman-un:R9C:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:unem:R16A:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:unem:R15B:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:unem:R15A:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:unem:R14B:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:unem:R14A:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:unem:R11B:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:unem:R11A:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:unem:R10C:*:*:*:*:*:*:*

* cpe:2.3:a:hitachienergy:unem:R9C:*:*:*:*:*:*:*

NVD Source

Risk Analysis

The affected products use a default encryption key for DES, which can be leveraged by an attacker to access sensitive information and gain unauthorized control over managed network elements. This critical flaw carries a CVSS score of 9.8, indicating a high risk of total system compromise.

The vulnerability is remotely exploitable with low complexity, but no public exploit is known and it is not listed in the KEV database.

Recommended Action

Administrators must update to patched versions of FOXMAN-UN and UNEM to remove the use of default encryption keys.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2021-40342 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.