GHSA-5p3x-r448-pc62
Improper Verification of Cryptographic Signature in PySAML2
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
### 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 ensure that a signed SAML document is correctly signed. The default `CryptoBackendXmlSec1` backend is using the `xmlsec1` binary to verify the signature of signed SAML documents, but by default, `xmlsec1` accepts any type of key found within the given document. `xmlsec1` needs to be configured explicitly to only use only _x509 certificates_ for the verification process of the SAML document signature.
### Patches
Users should upgrade to pysaml2 `v6.5.0`.
### Workarounds
No workaround provided at this point.
### References
This issue has been reported in the past at the xmlsec1 mailing list:
https://www.aleksey.com/pipermail/xmlsec/2013/009717.html
### Credits
- Brian Wolff
### 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:[email protected])
References
External links from the advisory. They lead to third-party sites.
- https://github.com/IdentityPython/pysaml2/security/advisories/GHSA-5p3x-r448-pc62
- https://nvd.nist.gov/vuln/detail/CVE-2021-21239
- https://github.com/IdentityPython/pysaml2/commit/46578df0695269a16f1c94171f1429873f90ed99
- 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-2021-49.yaml
- https://lists.debian.org/debian-lts-announce/2021/02/msg00038.html
- https://pypi.org/project/pysaml2
- https://www.aleksey.com/pipermail/xmlsec/2013/009717.html