What is CVE-2017-1000071?

CVE-2017-1000071 is a high-severity vulnerability in Apereo Phpcas, classified under Improper Authentication. CVSS score: 8.1/10. Published 2017-07-17.

How severe is CVE-2017-1000071?

High severity. CVSS v3 base score is 8.1 out of 10.

Auth bypass in Apereo Phpcas

CVE-2017-1000071

Jasig phpCAS version 1.3.4 is vulnerable to an authentication bypass in the validateCAS20 function when configured to authenticate against an old CAS server.

Vulnerability class: Broken Authentication

Published 2017-07-17 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.035 (89.2th percentile), scored 2026-10-24.

Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 89.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.035 · newest: 0.035 · change: 0.000

Affected products

Apereo Phpcas — versions 1.3.4

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

github.com/Jasig/phpCAS/blob/master/docs/ChangeLog (Third Party Advisory)
www.securityfocus.com/bid/99609 (VDB Entry, Third Party Advisory, vdb-entry)
github.com/Jasig/phpCAS/issues/228 (Third Party Advisory)

Frequently asked questions

What is CVE-2017-1000071?: CVE-2017-1000071 is a high-severity vulnerability in Apereo Phpcas, classified under Improper Authentication. CVSS score: 8.1/10. Published 2017-07-17.
How severe is CVE-2017-1000071?: High severity. CVSS v3 base score is 8.1 out of 10.