CVE-2021-21238
MEDIUMDescription
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.
How to fix
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Exploit Intelligence
Moderate risk: more likely to be exploited than 61% of all known CVEs.
References
Related Vulnerabilities
Other CWE-347 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2018-16042 | Medium | 6.5 | 82% | - | - |
| CVE-2025-59718 | Critical | 9.8 | 66% | KEV | Fix |
| CVE-2025-25292 | Critical | 9.8 | 64% | - | Fix |
| CVE-2021-22160 | Critical | 9.8 | 53% | - | Fix |
| CVE-2013-3900 | Medium | 5.5 | 45% | KEV | - |
| CVE-2018-0114 | High | 7.5 | 43% | - | Fix |
Embed a live status badge for CVE-2021-21238
Markdown
[](https://tridentstack.com/cve/CVE-2021-21238)HTML
<a href="https://tridentstack.com/cve/CVE-2021-21238"><img src="https://tridentstack.com/cve/badge/CVE-2021-21238.svg" alt="CVE-2021-21238"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.