Vulnerability in D-Link Nuclias Connect

CVE-2025-34254

D-Link Nuclias Connect firmware versions <= 1.3.1.4 contain an observable response discrepancy vulnerability. The application's 'Login' endpoint returns distinct JSON responses depending on whether the supplied username is associated with an existing account. Because the responses differ in the `error.message`string value, an unauthenticated remote attacker can enumerate valid usernames/accounts on the server. NOTE: D-Link states that a fix is under development.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.010 (62.1th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 62.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-34254: held from 0.010 to 0.010.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-34254?
CVE-2025-34254 is a medium-severity vulnerability in D-Link Nuclias Connect, classified under Observable Response Discrepancy. CVSS score: 5.3/10. Published 2025-10-16.
How severe is CVE-2025-34254?
Medium severity. CVSS v3 base score is 5.3 out of 10.