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.

How to fix CVE-2021-21238

To remediate CVE-2021-21238, upgrade the affected package to a fixed version below.

• —upgrade to 6.5.1-1 or later
• —upgrade to 6.5.0 or later
• —upgrade to 1d8fd268f5bf887480a403a7a5ef8f048157cc14 or later

Is CVE-2021-21238 being exploited?

Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.

Affected packages (3)

• from 0, < 6.5.1-1
• from 0, < 6.5.0
• from 0, < 1d8fd268f5bf887480a403a7a5ef8f048157cc14 | from 0, < 6.5.0

CVSS scores

References (8)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2021-21238
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2021-21238
• PATCHgithub.com/IdentityPython/pysaml2
• WEBgithub.com/IdentityPython/pysaml2/commit/1d8fd268f5bf887480a403a7a5ef8f048157cc14