What is CVE-2021-38377?

CVE-2021-38377 is a medium-severity vulnerability in Open-Xchange Ox App Suite, classified under Use of Insufficiently Random Values. CVSS score: 6.1/10. Published 2021-11-22.

How severe is CVE-2021-38377?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Vulnerability in Open-Xchange Ox App Suite

CVE-2021-38377

OX App Suite through 7.10.5 allows XSS via JavaScript code in an anchor HTML comment within truncated e-mail, because there is a predictable UUID with HTML transformation results.

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

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.012 (65.8th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 66th percentile — 65.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.012 · change: +0.000

Affected products

Open-Xchange Ox App Suite

Weakness classification (CWE)

CWE-330 — Use of Insufficiently Random Values

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-2021-38377?: CVE-2021-38377 is a medium-severity vulnerability in Open-Xchange Ox App Suite, classified under Use of Insufficiently Random Values. CVSS score: 6.1/10. Published 2021-11-22.
How severe is CVE-2021-38377?: Medium severity. CVSS v3 base score is 6.1 out of 10.