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SAML XML Signature wrapping in PySAML2

Low severity GitHub Reviewed Published Jan 20, 2021 in IdentityPython/pysaml2 • Updated Feb 1, 2023

Package

pip pysaml2 (pip)

Affected versions

< 6.5.0

Patched versions

6.5.0

Description

Impact

All users of pysaml2 that use the default CryptoBackendXmlSec1 backend and need to verify signed SAML documents are impacted. pysaml2 <= 6.4.1 does not validate the SAML document against an XML schema. This allows invalid XML documents to trick the verification process, by presenting elements with a valid signature inside elements whose content has been malformed. The verification is offloaded to xmlsec1 and xmlsec1 will not validate every signature in the given document, but only the first it finds in the given scope.

Patches

Users should upgrade to pysaml2 v6.5.0.

Workarounds

No workaround provided at this point.

References

No references provided at this point.

Credits

  • Victor Schönfelder Garcia (isits AG International School of IT Security)
  • Juraj Somorovsky (Paderborn University)
  • Vladislav Mladenov (Ruhr University Bochum)

For more information

If you have any questions or comments about this advisory:

References

@c00kiemon5ter c00kiemon5ter published to IdentityPython/pysaml2 Jan 20, 2021
Reviewed Jan 21, 2021
Published to the GitHub Advisory Database Jan 21, 2021
Published by the National Vulnerability Database Jan 21, 2021
Last updated Feb 1, 2023

Severity

Low

Weaknesses

CVE ID

CVE-2021-21238

GHSA ID

GHSA-f4g9-h89h-jgv9

Source code

No known source code

Credits

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