CVE-2022-23740 is a critical vulnerability identified in GitHub Enterprise Server version 3.7.0, classified under CWE-88 (Improper Neutralization of Argument Delimiters in a Command). This vulnerability allows remote code execution (RCE) due to improper sanitization of command arguments, enabling an attacker to inject and execute arbitrary commands on the affected server. The exploit requires that the attacker has permission to create and build GitHub Pages using GitHub Actions, which means the attacker must have at least limited privileges within the GitHub Enterprise environment. The vulnerability was addressed and fixed in version 3.7.1 of GitHub Enterprise Server. The CVSS v3.1 base score is 8.8, indicating a high severity level, with the vector string AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. This means the attack can be performed remotely over the network with low attack complexity, requires low privileges, and no user interaction. The impact affects confidentiality, integrity, and availability, as the attacker can execute arbitrary code remotely, potentially leading to full system compromise. No known exploits in the wild have been reported to date. The vulnerability was responsibly disclosed through the GitHub Bug Bounty program. Given the nature of GitHub Enterprise Server as a platform for hosting private repositories and CI/CD pipelines, exploitation could lead to unauthorized access to sensitive source code, injection of malicious code into software builds, and disruption of development workflows.

For European organizations using GitHub Enterprise Server version 3.7.0, this vulnerability poses a significant risk. Successful exploitation could lead to unauthorized remote code execution on critical infrastructure hosting source code and build pipelines. This could result in theft or tampering of intellectual property, insertion of backdoors or malware into software releases, and disruption of software development and deployment processes. Organizations in sectors with high reliance on software integrity, such as finance, telecommunications, healthcare, and government, could face severe operational and reputational damage. Additionally, compromised GitHub Enterprise Servers could be used as pivot points for lateral movement within corporate networks, increasing the risk of broader network compromise. The requirement for low privileges to exploit means that insider threats or compromised user accounts with minimal permissions could trigger a full system compromise. The absence of known exploits in the wild reduces immediate risk but does not eliminate it, especially if attackers develop exploits targeting this vulnerability.

1. Immediate upgrade: Organizations should upgrade GitHub Enterprise Server from version 3.7.0 to 3.7.1 or later to apply the official patch that fixes this vulnerability. 2. Access control review: Restrict and audit permissions related to GitHub Pages creation and GitHub Actions workflows, ensuring only trusted users have these capabilities. 3. Monitoring and logging: Enable detailed logging of GitHub Actions executions and repository changes to detect suspicious activity indicative of exploitation attempts. 4. Network segmentation: Isolate GitHub Enterprise Server instances within secure network zones with strict ingress and egress controls to limit exposure. 5. Incident response preparedness: Develop and test incident response plans specific to source code repository compromise scenarios. 6. User training: Educate developers and administrators about the risks of privilege misuse and the importance of applying patches promptly. 7. Vulnerability scanning: Incorporate automated scanning for outdated GitHub Enterprise Server versions in asset management and vulnerability management programs. These steps go beyond generic advice by focusing on permissions related to GitHub Pages and Actions, emphasizing monitoring of build workflows, and network-level protections tailored to GitHub Enterprise Server deployments.