CVE-2022-23741 is a high-severity authorization vulnerability (CWE-863) affecting GitHub Enterprise Server versions 3.3 through 3.6. This flaw allows a scoped user-to-server token, which normally has limited privileges, to be escalated to full administrative or owner privileges. The vulnerability arises due to incorrect authorization checks when handling scoped tokens associated with GitHub Apps. An attacker must already possess an account with admin-level access to exploit this issue, specifically by installing a malicious GitHub App. Once exploited, the attacker can leverage the escalated privileges to gain full control over the GitHub Enterprise Server instance, potentially compromising the confidentiality, integrity, and availability of repositories, user data, and organizational settings. The vulnerability was responsibly disclosed via the GitHub Bug Bounty program and has been addressed in patched versions 3.3.17, 3.4.12, 3.5.9, and 3.6.5. No known exploits have been reported in the wild to date. The CVSS v3.1 base score is 7.2, reflecting network attack vector, low attack complexity, high privileges required, no user interaction, and high impact on confidentiality, integrity, and availability. This vulnerability is particularly critical in environments where GitHub Enterprise Server is used to manage sensitive codebases and development workflows, as unauthorized administrative access could lead to code tampering, data leakage, or disruption of development pipelines.

For European organizations, the impact of this vulnerability can be significant, especially for those relying on GitHub Enterprise Server for internal software development and collaboration. Unauthorized escalation to admin privileges could lead to unauthorized code changes, insertion of malicious code, exposure of proprietary or personal data, and disruption of development operations. This could affect sectors with high regulatory requirements such as finance, healthcare, and critical infrastructure, potentially leading to compliance violations (e.g., GDPR), reputational damage, and operational downtime. The ability to install malicious GitHub Apps with elevated privileges could also facilitate supply chain attacks, impacting not only the targeted organization but also their customers and partners. Given the widespread adoption of GitHub Enterprise Server in Europe, particularly among large enterprises and government agencies, the vulnerability poses a substantial risk if unpatched.

European organizations should immediately verify their GitHub Enterprise Server versions and upgrade to the fixed releases (3.3.17, 3.4.12, 3.5.9, or 3.6.5) as applicable. Beyond patching, organizations should audit existing GitHub Apps installed on their servers to detect any unauthorized or suspicious applications, especially those installed by users with admin privileges. Implement strict access controls and monitoring around admin accounts to detect unusual activities related to app installations or privilege escalations. Employ multi-factor authentication (MFA) for all admin users to reduce the risk of compromised credentials. Regularly review and limit the number of users with admin privileges to the minimum necessary. Additionally, enable detailed logging and alerting for GitHub App installations and privilege changes to facilitate rapid detection and response. Consider integrating GitHub Enterprise Server logs with centralized Security Information and Event Management (SIEM) systems for enhanced monitoring. Finally, conduct security awareness training for administrators to recognize and prevent potential misuse of admin privileges.