PySAML2 is a pure python implementation of SAML Version 2 Standard. PySAML2 before 6.5.0 has an improper verification of cryptographic signature vulnerability. Users of pysaml2 that use the default CryptoBackendXmlSec1 backend and need to verify signed SAML documents are impacted. PySAML2 does not ensure that a signed SAML document is correctly signed. The default CryptoBackendXmlSec1 backend is using the xmlsec1 binary to verify the signature of signed SAML documents, but by default xmlsec1 accepts any type of key found within the given document. xmlsec1 needs to be configured explicitly to only use only _x509 certificates_ for the verification process of the SAML document signature. This is fixed in PySAML2 6.5.0.

The remote Ubuntu 16.04 ESM host has packages installed that are affected by a vulnerability as referenced in the USN-5066-2 advisory.

    USN-5066-1 fixed a vulnerability in PySAML2. This update provides the corresponding update for Ubuntu     16.04 ESM.



Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Ubuntu 18.04 LTS / 20.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-5066-1 advisory.

    Brian Wolff discovered that PySAML2 incorrectly validated cryptographic signatures. A remote attacker     could possibly use this issue to alter SAML documents.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Several issues have been found in python-pysaml2, a pure python implementation of SAML Version 2 Standard.

CVE-2017-1000433

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

CVE-2021-21239

pysaml2 has an improper verification of cryptographic signature vulnerability. Users of pysaml2 that use the default CryptoBackendXmlSec1 backend and need to verify signed SAML documents are impacted. PySAML2 does not ensure that a signed SAML document is correctly signed. The default CryptoBackendXmlSec1 backend is using the xmlsec1 binary to verify the signature of signed SAML documents, but by default xmlsec1 accepts any type of key found within the given document. xmlsec1 needs to be configured explicitly to only use only
_x509 certificates_ for the verification process of the SAML document signature.

For Debian 9 stretch, these problems have been fixed in version 3.0.0-5+deb9u2.

We recommend that you upgrade your python-pysaml2 packages.

For the detailed security status of python-pysaml2 please refer to its security tracker page at:
https://security-tracker.debian.org/tracker/python-pysaml2

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

pysaml2 Releases :

Fix processing of invalid SAML XML documents - CVE-2021-21238

Fix unspecified xmlsec1 key-type preference - CVE-2021-21239

ID	Name	Product	Family	Severity
153361	Ubuntu 16.04 ESM : PySAML2 vulnerability (USN-5066-2)	Nessus	Ubuntu Local Security Checks	medium
153139	Ubuntu 18.04 LTS / 20.04 LTS : PySAML2 vulnerability (USN-5066-1)	Nessus	Ubuntu Local Security Checks	medium
146893	Debian DLA-2577-1 : python-pysaml2 security update	Nessus	Debian Local Security Checks	high
145469	FreeBSD : pysaml2 -- multiple vulnerabilities (fb67567a-5d95-11eb-a955-08002728f74c)	Nessus	FreeBSD Local Security Checks	medium

Detections

Analytics

CVE-2021-21239

medium

Tenable Plugins

medium

medium

high

medium