Overview

This is the initial version of an Apereo CAS project vulnerability disclosure, describing an issue in CAS that affects surrogate authentication and impersonation.

This post will be updated with additional details once the grace period has passed.

Affected Deployments

The attack vector applies to deployments of the CAS server for the following versions:

- 5.3.x
- 6.0.x
- 6.1.x

Severity

It is recommended that upgrades be carried out to removes any chances of security breaches.

Patching

Patch releases are available to address CAS deployments. Upgrades to the next patch version for each release should be a drop-in replacement.

Timeline

The issue was originally reported to the CAS application security team on December 18th, 2019 and upon confirmation, CAS was patched on December 20th.

Procedure

5.3.x

Modify your CAS overlay to point to version 5.3.15. A snippet of a pom.xml for a CAS overlay follows:

<properties>
    <cas.version>5.3.15</cas.version>
</properties>

6.0.x

Modify your CAS overlay to point to the version 6.0.8. A snippet of a gradle.properties for a CAS overlay follows:

cas.version=6.0.8

6.1.x

Modify your CAS overlay to point to the version 6.1.3. A snippet of a gradle.properties for a CAS overlay follows:

cas.version=6.1.3

6.2.x

Modify your CAS overlay to point to the version 6.2.0-RC2, when released. A snippet of a gradle.properties for a CAS overlay follows:

cas.version=6.2.0-RC2

Support

CAS is Apache v2 open source software under the sponsorship of the Apereo Foundation, supported by community volunteers and enthusiasts. Support options may be found here.

Resources

• CAS Security Vulnerability Response Model
• CAS Maintenance Policy

On behalf of the CAS Application Security working group,

Misagh Moayyed