What is CVE-2021-28973?

CVE-2021-28973 is a medium-severity vulnerability in Perforce Helix Alm, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 4.9/10. Published 2021-04-13.

How severe is CVE-2021-28973?

Medium severity. CVSS v3 base score is 4.9 out of 10.

XXE in Perforce Helix Alm

CVE-2021-28973

The XML Import functionality of the Administration console in Perforce Helix ALM 2020.3.1 Build 22 accepts XML input data that is parsed by insecurely configured software components, leading to XXE attacks.

Vulnerability class: XXE (XML External Entity)

Published 2021-04-13 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.009 (57.8th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 57.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Perforce Helix Alm — versions 2020.3.1

Weakness classification (CWE)

CWE-611 — Improper Restriction of XML External Entity Reference (XXE)

References

www.compass-security.com/fileadmin/Research/Advisories/2021-01_CSNC-2021-005_He… (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-28973?: CVE-2021-28973 is a medium-severity vulnerability in Perforce Helix Alm, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 4.9/10. Published 2021-04-13.
How severe is CVE-2021-28973?: Medium severity. CVSS v3 base score is 4.9 out of 10.