PySAML2 before 5.0.0 does not check that the signature in a SAML document is enveloped and thus signature wrapping is effective, i.e., it is affected by XML Signature Wrapping (XSW). The signature information and the node/object that is signed can be in different places and thus the signature verification will succeed, but the wrong data will be used. This specifically affects the verification of assertion that have been signed.

Clever saml2-js 2.0 and earlier may incorrectly utilize the results of XML DOM traversal and canonicalization APIs in such a way that an attacker may be able to manipulate the SAML data without invalidating the cryptographic signature, allowing the attack to potentially bypass authentication to SAML service providers.

HTTPRedirect.php in the saml2 library in SimpleSAMLphp before 1.15.4 has an incorrect check of return values in the signature validation utilities, allowing an attacker to get invalid signatures accepted as valid by forcing an error during validation. This occurs because of a dependency on PHP functionality that interprets a -1 error code as a true boolean value.

The SAML2 library before 1.10.4, 2.x before 2.3.5, and 3.x before 3.1.1 in SimpleSAMLphp has a Regular Expression Denial of Service vulnerability for fraction-of-seconds data in a timestamp.

pysaml2 version 4.4.0 and older accept any password when run with python optimizations enabled. This allows attackers to log in as any user without knowing their password.

A vulnerability has been discovered in the Auth0 passport-wsfed-saml2 library affecting versions < 3.0.5. This vulnerability allows an attacker to impersonate another user and potentially elevate their privileges if the SAML identity provider does not sign the full SAML response (e.g., only signs the assertion within the response).

Python package pysaml2 version 4.4.0 and earlier reuses the initialization vector across encryptions in the IDP server, resulting in weak encryption of data.

XML External Entity (XXE) vulnerability in PySAML2 4.4.0 and earlier allows remote attackers to read arbitrary files via a crafted SAML XML request or response.

PySAML2 allows remote attackers to conduct XML external entity (XXE) attacks via a crafted SAML XML request or response.

The validateSignature method in the SAML2\Utils class in SimpleSAMLphp before 1.14.10 and simplesamlphp/saml2 library before 1.9.1, 1.10.x before 1.10.3, and 2.x before 2.3.3 allows remote attackers to spoof SAML responses or possibly cause a denial of service (memory consumption) by leveraging improper conversion of return values to boolean.