CVE-2021-21238
MEDIUM6.5EPSS 0.14%SAML XML Signature wrapping in PySAML2
Published: 1/21/2021Modified: 4/28/2026
Description
PySAML2 is a pure python implementation of SAML Version 2 Standard. PySAML2 before 6.5.0 has an improper verification of cryptographic signature vulnerability. All users of pysaml2 that need to validate signed SAML documents are impacted. The vulnerability is a variant of XML Signature wrapping because it did not validate the SAML document against an XML schema. This allowed invalid XML documents to be processed and such a document can trick pysaml2 with a wrapped signature. This is fixed in PySAML2 6.5.0.
Affected packages (3)
- Debian/python-pysaml2from 0, < 6.5.1-1
- PyPI/pysaml2from 0, < 6.5.0
- PyPI/pysaml2from 0, < 1d8fd268f5bf887480a403a7a5ef8f048157cc14 | from 0, < 6.5.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N |
References (8)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2021-21238
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2021-21238
- PATCHhttps://github.com/IdentityPython/pysaml2
- WEBhttps://github.com/IdentityPython/pysaml2/commit/1d8fd268f5bf887480a403a7a5ef8f048157cc14
- WEBhttps://github.com/IdentityPython/pysaml2/releases/tag/v6.5.0
- WEBhttps://github.com/IdentityPython/pysaml2/security/advisories/GHSA-f4g9-h89h-jgv9
- WEBhttps://github.com/pypa/advisory-database/tree/main/vulns/pysaml2/PYSEC-2021-48.yaml
- WEBhttps://pypi.org/project/pysaml2