What’s Vulnerable › Vulnerabilities

CVE-2020-5390

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-01-13 · updated 2026-06-17
• Weakness: CWE-347

Description

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.

Affected products

• Canonical Ubuntu Linux: 16.04, 18.04, 19.04, 19.10
• Debian Linux: 8.0, 9.0, 10.0
• IdentityPython pysaml2: before 5.0.0 — fixed in 5.0.0

How to fix

Upgrade to a fixed version: IdentityPython pysaml2 5.0.0. Check the vendor advisory for mitigations.

References

• https://github.com/IdentityPython/pysaml2/commit/5e9d5acbcd8ae45c4e736ac521fd2df5b1c62e25
• https://github.com/IdentityPython/pysaml2/commit/f27c7e7a7010f83380566a219fd6a290a00f2b6e
• https://github.com/IdentityPython/pysaml2/releases
• https://github.com/IdentityPython/pysaml2/releases/tag/v5.0.0
• https://lists.debian.org/debian-lts-announce/2020/02/msg00025.html
• https://pypi.org/project/pysaml2/5.0.0/
• https://usn.ubuntu.com/4245-1/
• https://www.debian.org/security/2020/dsa-4630
• https://github.com/IdentityPython/pysaml2/commit/5e9d5acbcd8ae45c4e736ac521fd2df5b1c62e25
• https://github.com/IdentityPython/pysaml2/commit/f27c7e7a7010f83380566a219fd6a290a00f2b6e
• https://github.com/IdentityPython/pysaml2/releases
• https://github.com/IdentityPython/pysaml2/releases/tag/v5.0.0

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