Central Authentication Service

Apereo CAS 7.3.0 before 8.0.0-RC6 contains a cryptographic vulnerability that allows remote unauthenticated attackers to recover plaintext conversation state by exploiting AES-GCM initialization vector reuse across the server lifetime. Attackers can collect multiple client-side webflow execution tokens from the unauthenticated login page and perform known-plaintext analysis to decrypt the webflow conversation state due to keystream reuse caused by a fixed all-zero IV paired with the same encryption key.

Published: 2026-07-02T19:42:51.897Z
Updated: 2026-07-14T22:03:25.158Z

Improper Authentication vulnerability in Apereo CAS in jakarta.servlet.http.HttpServletRequest.getRemoteAddr method allows Multi-Factor Authentication bypass.This issue affects CAS: through 7.0.0-RC7. It is unknown whether in new versions the issue will be fixed. For the date of publication there is no patch, and the vendor does not treat it as a vulnerability.

Published: 2023-11-09T13:41:38.189Z
Updated: 2025-02-26T21:25:31.425Z

Apereo CAS is an open source multilingual single sign-on solution for the web. Apereo CAS can be configured to use authentication based on client X509 certificates. These certificates can be provided via TLS handshake or a special HTTP header, such as “ssl_client_cert”. When checking the validity of the provided client certificate, X509CredentialsAuthenticationHandler performs check that this certificate is not revoked. To do so, it fetches URLs provided in the “CRL Distribution Points” extension of the certificate, which are taken from the certificate itself and therefore can be controlled by a malicious user. If the CAS server is configured to use an LDAP server for x509 authentication with a password, for example by setting a “cas.authn.x509.ldap.ldap-url” and “cas.authn.x509.ldap.bind-credential” properties, X509CredentialsAuthenticationHandler fetches revocation URLs from the certificate, which can be LDAP urls. When making requests to this LDAP urls, Apereo CAS uses the same password as for initially configured LDAP server, which can lead to a password leak. An unauthenticated user can leak the password used to LDAP connection configured on server. This issue has been addressed in version 6.6.6. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Published: 2023-06-27T17:10:47.930Z
Updated: 2024-11-27T19:03:39.948Z

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

Published: 2021-12-07T21:10:49.000Z
Updated: 2024-08-04T03:38:49.276Z

Apereo CAS 5.3.x before 5.3.16, 6.x before 6.1.7.2, 6.2.x before 6.2.4, and 6.3.x before 6.3.0-RC4 mishandles secret keys with Google Authenticator for multifactor authentication.

Published: 2020-10-16T15:22:48.000Z
Updated: 2024-08-04T16:11:35.538Z