CVE-2020-5390: Improper Verification of Cryptographic Signature in PySAML2

CVE-2020-5390 · Severity: low · CVSS 3.1 · Published 2020-01-13

PySAML2 before 5.0.0 does not check that the signature in a SAML document is enveloped and thus signature wrapping is effective, i.e., it is affected by XML Signature Wrapping (XSW). The signature information and the node/object that is signed can be in different places and thus the signature verification will succeed, but the wrong data will be used. This specifically affects the verification of assertion that have been signed.

Technologies: pysaml2 (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2020-5390 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2020-5390 being exploited in the wild.
How severe is CVE-2020-5390?
Low severity, with a CVSS score of 3.1, published 13 January 2020.
Which products and versions are affected?
pysaml2 (PyPI) ECOSYSTEM:introduced=0,fixed=5.0.0, GIT:introduced=0,fixed=f27c7e7a7010f83380566a219fd6a290a00f2b6e,fixed=5e9d5acbcd8ae45c4e736ac521fd2df5b1c62e25|ECOSYSTEM:introduced=0,fixed=5.0.0.
Is there a fix for CVE-2020-5390?
Yes. pysaml2 (PyPI): upgrade to 5.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2020-5390?
Check whether you run pysaml2 (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • pysaml2 (PyPI): upgrade to 5.0.0 or later
    pip install "pysaml2>=5.0.0"

Affected products

  • pysaml2 (PyPI) ECOSYSTEM:introduced=0,fixed=5.0.0, GIT:introduced=0,fixed=f27c7e7a7010f83380566a219fd6a290a00f2b6e,fixed=5e9d5acbcd8ae45c4e736ac521fd2df5b1c62e25|ECOSYSTEM:introduced=0,fixed=5.0.0

Identifiers

  • CVE-2020-5390
  • GHSA-qf7v-8hj3-4xw7
  • PYSEC-2020-94

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