CVE-2024-3092 is a high-severity vulnerability affecting GitLab Community Edition (CE) and Enterprise Edition (EE) versions starting from 16.9 up to but not including 16.9.4, and versions starting from 16.10 up to but not including 16.10.2. The vulnerability is classified as CWE-79, which corresponds to improper neutralization of input during web page generation, commonly known as Cross-Site Scripting (XSS). Specifically, this is a Stored XSS vulnerability that arises when using the diff viewer feature in GitLab. An attacker can craft a malicious payload that, when stored and later rendered by the diff viewer, executes arbitrary JavaScript code in the context of the victim's browser. This can lead to unauthorized actions performed on behalf of the victim, such as stealing session tokens, performing actions with the victim’s privileges, or manipulating the GitLab interface. The CVSS 3.1 base score is 8.7, indicating a high severity with network attack vector, low attack complexity, requiring privileges (PR:L), and user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact on confidentiality and integrity is high, while availability is not impacted. No known exploits in the wild have been reported yet. The vulnerability was published on April 12, 2024, and has been assigned by GitLab and enriched by CISA. No patch links were provided in the data, but it is expected that GitLab has or will release patches in versions 16.9.4 and 16.10.2 to address this issue.

For European organizations, this vulnerability poses a significant risk, especially for those relying heavily on GitLab for source code management, CI/CD pipelines, and collaboration. Exploitation could allow attackers to execute arbitrary scripts in the context of authenticated users, potentially leading to session hijacking, unauthorized code changes, or disclosure of sensitive project information. This can disrupt development workflows, compromise intellectual property, and lead to further lateral movement within the organization’s network. Given GitLab’s widespread adoption across various sectors in Europe, including finance, government, and technology, the impact could be broad and severe. The requirement for some level of privileges and user interaction somewhat limits the attack surface but does not eliminate risk, especially in environments with many users and complex permissions. Additionally, the changed scope indicates that the vulnerability could affect multiple components or users beyond the initially targeted one, increasing potential damage.

European organizations should prioritize upgrading GitLab instances to versions 16.9.4 or 16.10.2 or later, where this vulnerability is patched. Until patches are applied, organizations should restrict access to the diff viewer feature to trusted users only and consider disabling it if feasible. Implement strict input validation and output encoding on any custom integrations or plugins interacting with GitLab’s diff viewer to reduce injection risks. Employ Content Security Policy (CSP) headers to limit the impact of potential XSS payloads by restricting script execution sources. Monitor GitLab logs for unusual activities, especially related to diff viewer usage, and educate users about the risks of interacting with untrusted links or payloads within GitLab. Additionally, review and tighten user privileges to minimize the number of users with access rights that could be exploited. Regularly audit GitLab configurations and ensure that multi-factor authentication (MFA) is enforced to reduce the risk of session hijacking.