Risk | Medium |
Patch available | YES |
Number of vulnerabilities | 1 |
CVE-ID | CVE-2021-21239 |
CWE-ID | CWE-347 |
Exploitation vector | Network |
Public exploit | N/A |
Vulnerable software Subscribe |
Ubuntu Operating systems & Components / Operating system python3-pysaml2 (Ubuntu package) Operating systems & Components / Operating system package or component python-pysaml2 (Ubuntu package) Operating systems & Components / Operating system package or component |
Vendor | Canonical Ltd. |
Security Bulletin
This security bulletin contains one medium risk vulnerability.
EUVDB-ID: #VU50365
Risk: Medium
CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-21239
CWE-ID:
CWE-347 - Improper Verification of Cryptographic Signature
Exploit availability: No
DescriptionThe vulnerability allows a remote non-authenticated attacker to manipulate data.
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.
MitigationUpdate the affected package python-pysaml2 to the latest version.
Vulnerable software versionsUbuntu: 18.04 - 21.04
python3-pysaml2 (Ubuntu package): before 6.1.0-0ubuntu1.21.04.1
python-pysaml2 (Ubuntu package): before 4.0.2-0ubuntu3.2
External linkshttp://ubuntu.com/security/notices/USN-5066-1
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.