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.

Published: 2017-07-17 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-1000071 is rated High Risk (66.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.53%). EPSS rose +3.28% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2017-1000071

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.25% 3.53% +3.28%
2 2025-03-30 2.76% 0.25% -2.51%
3 2025-03-29 — 2.76% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-1000071

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.0 HIGH
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2017-1000071

OS Trackers for CVE-2017-1000071

vendor priority summary link
debian not yet assigned CVE-2017-1000071 not yet assigned priority: Debian including 1 source packages (php-cas), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2017-1000071
ubuntu low CVE-2017-1000071 low priority: Ubuntu including 1 source packages (php-cas), 22 status rows across 22 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial, yakkety, zesty): not-affected 14, ignored 4, needed 2, DNE 1, released 1. https://ubuntu.com/security/CVE-2017-1000071

Affected software / configurations for CVE-2017-1000071

Vendor Product Version Raw CPE
apereo phpcas 1.3.4 cpe:2.3:a:apereo:phpcas:1.3.4:*:*:*:*:*:*:*

References for CVE-2017-1000071

cvelogic Threat Intelligence