SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-21238

PySAML2 before 6.5.0 has an improper verification of cryptographic signature vulnerability.

MEDIUM 6.5EPSS 1.08%

Does this matter?

Lower severity and a low EPSS score (1.08%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
EPSS
1.08% probability · 63th percentile
CISA KEV
Not listed
Weakness
CWE-347
Affected
pysaml2 project/pysaml2
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.