How severe is CVE-2017-1000071?

CVE-2017-1000071 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2017-1000071 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-1000071?

CVE-2017-1000071 affects Apereo Phpcas. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-1000071?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2017-1000071 published?

CVE-2017-1000071 was published on 2017-07-17 and last updated on 2026-06-17.

CVE-2017-1000071

CVE-2017-1000071 is a high-severity vulnerability in Apereo Phpcas with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 6.8
EPSS exploit prediction: 4% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Apereo Phpcas
Published: 2017-07-17
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2017-1000071?: CVE-2017-1000071 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2017-1000071 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-1000071?: CVE-2017-1000071 affects Apereo Phpcas. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-1000071?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2017-1000071 published?: CVE-2017-1000071 was published on 2017-07-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:apereo:phpcas:1.3.4:*:*:*:*:*:*:*

More vulnerabilities in Apereo Phpcas

CVE-2014-4172 — Critical (CVSS 9.8): A URL parameter injection vulnerability was found in the back-channel ticket validation step of the CAS protocol in…
CVE-2022-39369 — High (CVSS 8.0): phpCAS is an authentication library that allows PHP applications to easily authenticate users via a Central…
CVE-2010-3692 — Medium (CVSS 6.4): Directory traversal vulnerability in the callback function in client.php in phpCAS before 1.1.3, when proxy mode is…
CVE-2012-5583 — Medium (CVSS 5.8): phpCAS before 1.3.2 does not verify that the server hostname matches a domain name in the subject's Common Name (CN) or…
CVE-2012-1105 — Medium (CVSS 5.5): An Information Disclosure vulnerability exists in the Jasig Project php-pear-CAS 1.2.2 package in the /tmp directory.…
CVE-2012-1104 — Medium (CVSS 5.3): A Security Bypass vulnerability exists in the phpCAS 1.2.2 library from the jasig project due to the way proxying of…

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Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

Browse all CWE-287 (Improper Authentication) vulnerabilities →