Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-31399

21
FAUCET Score

CVE-2021-31399 describes a man-in-the-middle vulnerability in 2N Access Unit 2.0 devices running firmware version 2.31.0.40.5, where an attacker can impersonate the web relay. This medium-severity vulnerability (CVSS 5.9) has a high attack complexity but could lead to a high impact on integrity if successfully exploited. There is currently no evidence of active exploitation, public exploit code, or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
2.31.0.40.5CPE matchmatch criteria
cpe:2.3:o:2n:access_unit_2.0_firmware:2.31.0.40.5:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

4.6MEDIUM

CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L

Attack Vector
ADJACENT_NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
NONE
Availability Impact
LOW
Exploitability Score
2.1
Impact Score
2.5
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.85%
Probability of exploitation in next 30 days
EPSS Percentile
54.3%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0085 is in the 12th percentile among its peer group of 19,955 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

cds.thalesgroup.com / en/tcs-cert/CVE-2021-31399
excellium-services.com / cert-xlm-advisory/cve-2021-31399
Third Party Advisory
2n.cz / en_GB/products/ip-access-control/2n-access-unit-2
Vendor Advisory