How severe is CVE-2021-31399?

CVE-2021-31399 has a CVSS 3.x base score of 4.6, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability low.

Is CVE-2021-31399 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-31399?

CVE-2021-31399 affects 2n Access Unit 2.0 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-31399?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-31399 published?

CVE-2021-31399 was published on 2021-08-13 and last updated on 2026-06-17.

CVE-2021-31399

CVE-2021-31399 is a medium-severity vulnerability in 2n Access Unit 2.0 Firmware with a CVSS 3.x base score of 4.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-295.

Key facts

Severity: Medium (CVSS 3.x base score 4.6)
CVSS v2: 4.3
EPSS exploit prediction: 1% (54th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: 2n Access Unit 2.0 Firmware
Published: 2021-08-13
Last modified: 2026-06-17

Description

On 2N Access Unit 2.0 2.31.0.40.5 devices, an attacker can pose as the web relay for a man-in-the-middle attack.

Frequently asked questions

What is CVE-2021-31399?: On 2N Access Unit 2.0 2.31.0.40.5 devices, an attacker can pose as the web relay for a man-in-the-middle attack.
How severe is CVE-2021-31399?: CVE-2021-31399 has a CVSS 3.x base score of 4.6, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability low.
Is CVE-2021-31399 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-31399?: CVE-2021-31399 affects 2n Access Unit 2.0 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-31399?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-31399 published?: CVE-2021-31399 was published on 2021-08-13 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:2n:access_unit_2.0_firmware:2.31.0.40.5:*:*:*:*:*:*:*

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