Vulnerability Details : CVE-2021-21239
PySAML2 is a pure python implementation of SAML Version 2 Standard. PySAML2 before 6.5.0 has an improper verification of cryptographic signature vulnerability. Users of pysaml2 that use the default CryptoBackendXmlSec1 backend and need to verify signed SAML documents are impacted. PySAML2 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. This is fixed in PySAML2 6.5.0.
Products affected by CVE-2021-21239
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
- cpe:2.3:a:pysaml2_project:pysaml2:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-21239
0.20%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 58 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-21239
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
4.3
|
MEDIUM | AV:N/AC:M/Au:N/C:N/I:P/A:N |
8.6
|
2.9
|
NIST | |
6.5
|
MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N |
2.8
|
3.6
|
NIST | |
6.5
|
MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N |
2.8
|
3.6
|
GitHub, Inc. |
CWE ids for CVE-2021-21239
-
The product does not verify, or incorrectly verifies, the cryptographic signature for data.Assigned by: security-advisories@github.com (Primary)
References for CVE-2021-21239
-
https://github.com/IdentityPython/pysaml2/security/advisories/GHSA-5p3x-r448-pc62
Unspecified xmlsec1 key-type preference · Advisory · IdentityPython/pysaml2 · GitHubThird Party Advisory
-
https://www.aleksey.com/pipermail/xmlsec/2013/009717.html
[xmlsec] Xmlsec preferring KeyValue element over explicitly loaded public keys?Exploit;Mailing List;Third Party Advisory
-
https://github.com/IdentityPython/pysaml2/commit/46578df0695269a16f1c94171f1429873f90ed99
Merge pull request from GHSA-5p3x-r448-pc62 · IdentityPython/pysaml2@46578df · GitHubPatch;Third Party Advisory
-
https://github.com/IdentityPython/pysaml2/releases/tag/v6.5.0
Release Version 6.5.0 · IdentityPython/pysaml2 · GitHubThird Party Advisory
-
https://pypi.org/project/pysaml2
pysaml2 · PyPIProduct;Third Party Advisory
-
https://lists.debian.org/debian-lts-announce/2021/02/msg00038.html
[SECURITY] [DLA 2577-1] python-pysaml2 security updateMailing List;Third Party Advisory
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