CVE-2024-9487 in GitHub
Summary
by MITRE • 10/11/2024
An improper verification of cryptographic signature vulnerability was identified in GitHub Enterprise Server that allowed SAML SSO authentication to be bypassed resulting in unauthorized provisioning of users and access to the instance. Exploitation required the encrypted assertions feature to be enabled, and the attacker would require direct network access as well as a signed SAML response or metadata document. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.15 and was fixed in versions 3.11.16, 3.12.10, 3.13.5, and 3.14.2. This vulnerability was reported via the GitHub Bug Bounty program.
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Analysis
by VulDB Data Team • 11/15/2024
The vulnerability CVE-2024-9487 represents a critical cryptographic signature verification flaw within GitHub Enterprise Server's SAML Single Sign-On implementation that fundamentally undermines the security of identity management processes. This weakness specifically targets the cryptographic validation mechanisms that should ensure the integrity and authenticity of SAML assertions, creating a pathway for malicious actors to bypass authentication controls. The vulnerability's impact extends beyond simple access control, as it enables unauthorized user provisioning and complete administrative access to the affected GitHub Enterprise instance, making it particularly dangerous for organizations relying on SAML-based authentication for their development infrastructure.
The technical exploitation of this vulnerability requires specific conditions that must be met for successful attack execution. Attackers need to have direct network access to the target server and must possess either a valid signed SAML response or metadata document that can be manipulated to bypass signature verification. The flaw becomes apparent when the encrypted assertions feature is enabled, which is a common configuration in enterprise environments seeking to protect sensitive authentication data in transit. This particular implementation issue stems from inadequate cryptographic validation procedures that fail to properly verify digital signatures, allowing crafted malicious payloads to be accepted as legitimate authentication tokens. The vulnerability aligns with CWE-322, which addresses the weakness of inadequate key exchange, and CWE-347, which covers improper verification of cryptographic signatures, both of which are fundamental security principles in cryptographic system design.
The operational impact of CVE-2024-9487 is severe and multifaceted, affecting organizations that depend on GitHub Enterprise Server for their code management and collaboration infrastructure. Successful exploitation allows attackers to provision unauthorized users with arbitrary access levels, potentially including administrative privileges, which could lead to complete compromise of the development environment. This vulnerability particularly affects organizations using SAML SSO configurations, where the security model relies heavily on cryptographic verification to maintain trust boundaries between identity providers and service providers. The attack vector requires direct network access, which suggests that organizations with proper network segmentation and access controls may be partially protected, but the risk remains significant for those with exposed administrative interfaces or inadequate network monitoring. The vulnerability's exploitation potential is enhanced by the fact that it was discovered through the GitHub Bug Bounty program, indicating that it represents a real-world threat that security researchers have identified and documented.
Organizations must implement immediate mitigation strategies to address this vulnerability, beginning with upgrading to the patched versions 3.11.16, 3.12.10, 3.13.5, and 3.14.2 as recommended by GitHub. The upgrade process should be prioritized for all affected GitHub Enterprise Server instances, particularly those with SAML SSO configurations and encrypted assertions enabled. Network-level protections should include implementing strict access controls and monitoring for unauthorized network access attempts to the SAML endpoints. Security teams should also conduct thorough audits of their SAML configurations to identify any potential misconfigurations that could be exploited in conjunction with this vulnerability. The remediation process must include verification that cryptographic signature validation is properly functioning and that all SAML responses and metadata documents are correctly validated before being processed. Organizations should also consider implementing additional monitoring for suspicious user provisioning activities and unauthorized access attempts that could indicate exploitation attempts. This vulnerability serves as a reminder of the critical importance of proper cryptographic signature verification in authentication systems and the potential consequences when such verification fails, aligning with ATT&CK technique T1566 which covers credential harvesting through phishing and other social engineering methods that can be enhanced by bypassing authentication controls.