Multiple SAML libraries flaws allow hackers to bypass authentication to SAML service providers

SAML libraries

Unified authentication mechanism SSO SAML recently disclosed security bypass vulnerability, SAML, and OAuth, OpenID, CAS par. An attacker using the SAML vulnerability can verify his account without having to know the victim’s password. The vulnerability is associated with 6 CVE IDs and currently affects 5 vendors. US-CERT issued a warning notice.

The vulnerability affects SAML (Secure Assertion Markup Language), an XML-based markup language commonly used to exchange authentication and authorization data between parties.

SAML has the single most important use of single sign-on (SSO) solutions, which allows users to log in to a single identity account. Unlike other shared authentication schemes such as OAuth, OpenID, OpenID Connect, and Facebook Connect-SSO, it stores the user’s identity on the central server where the user owns the account.

Image: medium

When users try to log in to other enterprise applications, these applications (Service Providers – SPs) make requests to the local SSO server (Identity Provider – IdP) through SAML.

In a report released later today, researchers at Duo Labs uncovered a design flaw that affected various SSO software and a few open-source libraries designed to support SAML-based SSO operations.

The pitfalls are how these libraries handle XML annotations inserted in SAML response requests. For example, researchers have noticed that if an attacker inserts a comment in the username field in a way that destroys the username, an attacker may gain access to the legitimate user’s account.

The following CVEs are assigned:

CVE-2017-11427 – OneLogin’s “python-saml”
CVE-2017-11428 – OneLogin’s “ruby-saml”
CVE-2017-11429 – Clever’s “saml2-js”
CVE-2017-11430 – “OmniAuth-SAML”
CVE-2018-0489 – Shibboleth openSAML C++

Solution

Apply updatesAffected SAML service providers should update software to utilize the latest releases of affected SAML libraries. Please see the vendor list below for more information.

Vendor Information (Learn More)

Vendor Status Date Notified Date Updated
Clever, Inc. Affected 24 Jan 2018 26 Feb 2018
Duo Security Affected 22 Feb 2018
OmniAuth Affected 24 Jan 2018 06 Feb 2018
OneLogin Inc Affected 24 Jan 2018 27 Feb 2018
Shibboleth Consortium Affected 24 Jan 2018 06 Feb 2018
AssureBridge Not Affected 27 Feb 2018
Okta Inc. Not Affected 29 Jan 2018 27 Feb 2018
Box Unknown 23 Feb 2018 23 Feb 2018
Cisco Unknown 23 Feb 2018 23 Feb 2018
Danish e-Infrastructure Cooperation (WAYF) Unknown 24 Jan 2018 24 Jan 2018
Entr’ouvert Unknown 24 Jan 2018 24 Jan 2018
GitHub Unknown 24 Jan 2018 24 Jan 2018
Google Unknown 23 Feb 2018 23 Feb 2018
Microsoft Unknown 23 Feb 2018 23 Feb 2018
Pivotal Software, Inc. Unknown 24 Jan 2018 24 Jan 2018

Source: kb.cert.org