What is CVE-2021-3183?

CVE-2021-3183 is a high-severity vulnerability in Files Fat Client, classified under Insufficient Session Expiration. CVSS score: 7.5/10. Published 2021-01-19.

How severe is CVE-2021-3183?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Files Fat Client

CVE-2021-3183

Files.com Fat Client 3.3.6 allows authentication bypass because the client continues to have access after a logout and a removal of a login profile.

Published 2021-01-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.014 (72.0th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 72nd percentile — 72.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.014 · change: +0.002

Affected products

Files Fat Client — versions 3.3.6

Weakness classification (CWE)

CWE-613 — Insufficient Session Expiration

References

seclists.org/fulldisclosure/2021/Jan/20 (Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-3183?: CVE-2021-3183 is a high-severity vulnerability in Files Fat Client, classified under Insufficient Session Expiration. CVSS score: 7.5/10. Published 2021-01-19.
How severe is CVE-2021-3183?: High severity. CVSS v3 base score is 7.5 out of 10.