Buffer overflow in OpenSAML before 1.1.3 as used in Internet2 Shibboleth Service Provider software 1.3.x before 1.3.4, and XMLTooling before 1.2.2 as used in Internet2 Shibboleth Service Provider software 2.x before 2.2.1, allows remote attackers to cause a denial of service and possibly execute arbitrary code via a malformed encoded URL.

OpenSAML 2.x before 2.2.1 and XMLTooling 1.x before 1.2.1, as used by Internet2 Shibboleth Service Provider 2.x before 2.2.1, do not follow the KeyDescriptor element's Use attribute, which allows remote attackers to use a certificate for both signing and encryption when it is designated for just one purpose, potentially weakening the intended security application of the certificate.

Shibboleth XMLTooling-C before 1.6.3, as used in Shibboleth Service Provider before 2.6.0 on Windows and other products, mishandles digital signatures of user attribute data, which allows remote attackers to obtain sensitive information or conduct impersonation attacks via a crafted DTD.

Shibboleth XMLTooling-C before 1.6.4, as used in Shibboleth Service Provider before 2.6.1.4 on Windows and other products, mishandles digital signatures of user data, which allows remote attackers to obtain sensitive information or conduct impersonation attacks via crafted XML data. NOTE: this issue exists because of an incomplete fix for CVE-2018-0486.