CVE-2021-21238

Name	CVE-2021-21238
Description	PySAML2 is a pure python implementation of SAML Version 2 Standard. PySAML2 before 6.5.0 has an improper verification of cryptographic signature vulnerability. All users of pysaml2 that need to validate signed SAML documents are impacted. The vulnerability is a variant of XML Signature wrapping because it did not validate the SAML document against an XML schema. This allowed invalid XML documents to be processed and such a document can trick pysaml2 with a wrapped signature. This is fixed in PySAML2 6.5.0.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)
NVD severity	medium
Debian Bugs	980773

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
python-pysaml2 (PTS)	stretch	3.0.0-5+deb9u1	vulnerable
	stretch (security)	3.0.0-5+deb9u2	vulnerable
	buster, buster (security)	4.5.0-4+deb10u1	vulnerable
	bullseye, sid	6.5.1-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
python-pysaml2	source	(unstable)	6.5.1-1			980773

Notes

[stretch] - python-pysaml2 <no-dsa> (python3-xmlschema not available in stretch for fix)
https://github.com/IdentityPython/pysaml2/security/advisories/GHSA-f4g9-h89h-jgv9
https://github.com/IdentityPython/pysaml2/commit/3b707723dcf1bf60677b424aac398c0c3557641d