CVE-2021-21238
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Arch Fixed 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Fixed | 6.5.1-1 |
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 6.5.1-1 |
| sid | Fixed | 6.5.1-1 |
| forky | Fixed | 6.5.1-1 |
| bullseye | Fixed | 6.5.1-1 |
| bookworm | Fixed | 6.5.1-1 |
References
- https://github.com/IdentityPython/pysaml2/security/advisories/GHSA-f4g9-h89h-jgv9
- https://nvd.nist.gov/vuln/detail/CVE-2021-21238
- https://github.com/IdentityPython/pysaml2/commit/1d8fd268f5bf887480a403a7a5ef8f048157cc14
- https://github.com/IdentityPython/pysaml2
- https://github.com/IdentityPython/pysaml2/releases/tag/v6.5.0
- https://github.com/pypa/advisory-database/tree/main/vulns/pysaml2/PYSEC-2021-48.yaml
- https://pypi.org/project/pysaml2
- https://www.suse.com/security/cve/CVE-2021-21238.html
- https://security-tracker.debian.org/tracker/CVE-2021-21238
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.