What’s Vulnerable › Vulnerabilities

CVE-2021-42567

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 8.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-12-07 · updated 2026-06-17
• Weakness: CWE-79

Description

Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints.

Affected products

• Apereo Central Authentication Service: from 6.3.0 before 6.3.7.1; from 6.4.0 before 6.4.2 — fixed in 6.3.7.1, 6.4.2

How to fix

Upgrade to a fixed version: Apereo Central Authentication Service 6.3.7.1, 6.4.2. Check the vendor advisory for mitigations.

References

• https://apereo.github.io/2021/10/18/restvuln/
• https://github.com/apereo/cas/releases
• https://apereo.github.io/2021/10/18/restvuln/
• https://github.com/apereo/cas/releases

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