CVE-2021-21238: SAML XML Signature wrapping
First published: Thu Jan 21 2021(Updated: )
### Impact All users of pysaml2 that use the default `CryptoBackendXmlSec1` backend and need to verify signed SAML documents are impacted. `pysaml2 <= 6.4.1` does not validate the SAML document against an XML schema. This allows invalid XML documents to trick the verification process, by presenting elements with a valid signature inside elements whose content has been malformed. The verification is offloaded to `xmlsec1` and `xmlsec1` will not validate every signature in the given document, but only the first it finds in the given scope. ### Patches Users should upgrade to pysaml2 `v6.5.0`. ### Workarounds No workaround provided at this point. ### References No references provided at this point. ### Credits - Victor Schönfelder Garcia (isits AG International School of IT Security) - Juraj Somorovsky (Paderborn University) - Vladislav Mladenov (Ruhr University Bochum) ### For more information If you have any questions or comments about this advisory: * Open an issue in [pysaml2](https://github.com/IdentityPython/pysaml2) * Email us at [the incident-response address](mailto:incident-response@idpy.org)
Credit: security-advisories@github.com security-advisories@github.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Pysaml2 Project Pysaml2 | <6.5.0 | |
| pip/pysaml2 | <6.5.0 | 6.5.0 |
| <6.5.0 |
Never miss a vulnerability like this again
Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.
Reference Links
- https://github.com/IdentityPython/pysaml2/commit/1d8fd268f5bf887480a403a7a5ef8f048157cc14
- https://github.com/IdentityPython/pysaml2/releases/tag/v6.5.0
- https://github.com/IdentityPython/pysaml2/security/advisories/GHSA-f4g9-h89h-jgv9
- https://pypi.org/project/pysaml2
- https://nvd.nist.gov/vuln/detail/CVE-2021-21238
- https://github.com/pypa/advisory-database/tree/main/vulns/pysaml2/PYSEC-2021-48.yaml
- https://github.com/advisories/GHSA-f4g9-h89h-jgv9 (Advisory)
- collector/nvd-index
- agent/type
- collector/mitre-cve
- source/MITRE
- agent/title
- agent/weakness
- agent/severity
- agent/remedy
- collector/github-advisory-latest
- source/GitHub
- alias/GHSA-f4g9-h89h-jgv9
- alias/CVE-2021-21238
- agent/software-canonical-lookup
- agent/references
- agent/last-modified-date
- agent/description
- agent/first-publish-date
- agent/author
- agent/softwarecombine
- collector/nvd-cve
- source/NVD
- agent/event
- collector/github-advisory
- agent/tags
- agent/trending
- vendor/pysaml2 project
- canonical/pysaml2 project pysaml2
- package-manager/pip