CVE-2021-42567
Cross-site Scripting in Apereo CAS
Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints.
- Record
CVE-2021-42567- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
CVE List No score
Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints.
- Record
CVE-2021-42567- Updated
- 2026-11-02
EUVDEUVD-2021-2521 No score
Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints.
- Record
EUVD-2021-2521- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-gfhx-jjwq-63gv No score
Cross-site Scripting in Apereo CAS
Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints.
- Record
GHSA-gfhx-jjwq-63gv- Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints.
- Record
CVE-2021-42567- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-gfhx-jjwq-63gv No score
Cross-site Scripting in Apereo CAS
Apereo CAS through 6.4.1 allows XSS via POST requests sent to the REST API endpoints.
- Record
GHSA-gfhx-jjwq-63gv- Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
org.apereo.cas:cas-server-core-webMaven |
before 6.4.2 | 6.4.2 |
org.apereo.cas:cas-server-core-webMaven |
before 6.4.2, plus listed versions 5.0.05.0.0.M15.0.0.M25.0.0.M35.0.0.RC1 Show 45 moreShow less5.0.0.RC25.0.0.RC35.0.0.RC45.0.15.0.105.0.25.0.35.0.3.15.0.45.0.55.0.65.0.75.0.85.0.95.1.05.1.0-RC15.1.0-RC25.1.0-RC35.1.0-RC45.1.15.1.25.1.35.1.45.1.55.1.65.1.75.1.85.1.95.2.05.2.0-RC15.2.0-RC25.2.0-RC35.2.0-RC45.2.15.2.25.2.35.2.45.2.55.2.65.2.75.2.85.2.95.3.05.3.0-RC15.3.0-RC2 |
6.4.2 |
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Nuclei | Apereo CAS Cross-Site Scripting |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, Nuclei, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-42567 is a medium vulnerability (CVSS 6.1) in Apereo Central Authentication Service, published December 7, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 8.19%, the 94th percentile. Fixed in org.apereo.cas:cas-server-core-web 6.4.2.
References
Left out here: 92 versions. The JSON record has them.