GitLab has it released patches to address a critical flaw affecting Community Edition (CE) and Enterprise Edition (EE) that could lead to authentication bypass.
The vulnerability resides in the ruby-saml library (CVE-2024-45409, CVSS Score: 10.0), which could allow an attacker to log in as an arbitrary user on a vulnerable system. This was resolved last week.
The issue is caused by the library not validating the signature of the SAML response correctly. SAML, short for Security Assertion Markup Language, is a protocol that enables single sign-on (SSO) and the exchange of authentication and authorization data between different applications and websites.
“Thus, an unauthenticated attacker with access to any signed SAML document (from the IdP) can forge a SAML response/assert with arbitrary content. security advice. “This would allow an attacker to log in as an arbitrary user on a vulnerable system.”
It should be noted that the flaw also affects omniauth-saml, which sent own update (version 2.2.1) to update ruby-saml to version 1.17.
The latest patch from GitLab is to update the omniauth-saml dependencies to version 2.2.1 and ruby-saml to 1.17.0. This includes versions 17.3.3, 17.2.7, 17.1.8, 17.0.8, and 16.11.10.
As mitigation measures, GitLab encourages users of self-managed installations to enable two-factor authentication (2FA) for all accounts and prohibit SAML Two-Factor Bypass option.
GitLab does not mention exploitation of the flaw in the wild, but it does provide indicators of attempted or successful exploitation, suggesting that threat actors may be actively trying to exploit the flaws to gain access to vulnerable GitLab instances.
“Successful exploit attempts will result in SAML-related log events,” it said. “A successful exploit attempt will log any extern_id value set by the attacker attempting to exploit.”
“Failed exploitation attempts can raise a ValidationError from the RubySaml library. This could be for a variety of reasons related to the complexity of developing a working exploit.”
Development comes from the US Cybersecurity and Infrastructure Security Agency (CISA) added five security flaws of its known vulnerabilities (KEV) directory, including a recently disclosed critical bug affecting Apache HugeGraph-Server (CVE-2024-27348CVSS score: 9.8), based on evidence of active exploitation.
Federal Civil Executive Agencies (FCEB) have been advised to address identified vulnerabilities by October 9, 2024 to protect their networks from active threats.
