Improper Verification of Cryptographic Signature in PySAML2
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 assertions that have been signed.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | pysaml2 | < 5.0.0 | 5.0.0 |
References
- https://github.com/IdentityPython/pysaml2/releases/tag/v5.0.0
- https://github.com/IdentityPython/pysaml2/commit/f27c7e7a7010f83380566a219fd6a290a00f2b6e
- https://pypi.org/project/pysaml2/5.0.0/
- https://github.com/IdentityPython/pysaml2/commit/5e9d5acbcd8ae45c4e736ac521fd2df5b1c62e25
- https://github.com/IdentityPython/pysaml2/releases
- https://usn.ubuntu.com/4245-1/
- https://www.debian.org/security/2020/dsa-4630
- https://lists.debian.org/debian-lts-announce/2020/02/msg00025.html
- https://github.com/advisories/GHSA-qf7v-8hj3-4xw7
- https://nvd.nist.gov/vuln/detail/CVE-2020-5390
- https://github.com/IdentityPython/pysaml2
- https://github.com/IdentityPython/pysaml2/blob/master/CHANGELOG.md#500-2020-01-13
- https://github.com/pypa/advisory-database/tree/main/vulns/pysaml2/PYSEC-2020-94.yaml
- https://pypi.org/project/pysaml2/5.0.0
- https://usn.ubuntu.com/4245-1
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N- Weakness (CWE)
CWE-347- Platform
- Python (PyPI)
- Package
pysaml2- Disclosed
- 13.01.2020
- Updated
- 11.10.2026 11:20
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2020-94 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-qf7v-8hj3-4xw7 - CC BY 4.0
Vulnerability history: pysaml2
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 7
- First → latest
- 03.2017 01.2021
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 2
- High 2
- Medium 3
Disclosures per year
- 2017: 3
- 2018: 1
- 2019: 0
- 2020: 1
- 2021: 2
- 2022: 0
- 2023: 0
- 2024: 0
- 2025: 0
- 2026: 0
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