What is CVE-2021-38376?

CVE-2021-38376 is a medium-severity vulnerability in Open-Xchange Ox App Suite, classified under Improper Authentication. CVSS score: 5.3/10. Published 2021-11-22.

How severe is CVE-2021-38376?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Auth bypass in Open-Xchange Ox App Suite

CVE-2021-38376

OX App Suite through 7.10.5 has Incorrect Access Control for retrieval of session information via the rampup action of the login API call.

Vulnerability class: Broken Authentication

Published 2021-11-22 · last modified 2026-06-17.

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: 0.015 (73.3th percentile), scored 2026-10-07.

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 73.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.014 · newest: 0.015 · change: +0.000

Affected products

Open-Xchange Ox App Suite

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

www.open-xchange.com (Product)
seclists.org/fulldisclosure/2021/Nov/43 (Exploit, Mailing List, Third Party Advisory)
packetstormsecurity.com/files/165038/OX-App-Suite-7.10.5-Cross-Site-Scripting-I… (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-38376?: CVE-2021-38376 is a medium-severity vulnerability in Open-Xchange Ox App Suite, classified under Improper Authentication. CVSS score: 5.3/10. Published 2021-11-22.
How severe is CVE-2021-38376?: Medium severity. CVSS v3 base score is 5.3 out of 10.