Debian Security Advisory

DLA-2577-1 python-pysaml2 -- LTS security update

Date Reported:
26 Feb 2021
Affected Packages:
Security database references:
In the Debian bugtracking system: Bug 886423.
In Mitre's CVE dictionary: CVE-2017-1000433, CVE-2021-21239, CVE-2021-21239.
More information:

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:

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: