CVE-2023-6033 in Community Edition
Summary
by MITRE • 12/01/2023
Improper neutralization of input in Jira integration configuration in GitLab CE/EE, affecting all versions from 15.10 prior to 16.6.1, 16.5 prior to 16.5.3, and 16.4 prior to 16.4.3 allows attacker to execute javascript in victim's browser.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 11/20/2025
The vulnerability CVE-2023-6033 represents a critical cross-site scripting flaw in GitLab's integration configuration system that affects multiple versions of the platform. This security weakness exists within the Jira integration component where user input is not properly sanitized before being rendered in the web interface. The flaw allows attackers to inject malicious javascript code through the integration configuration parameters, which then executes in the context of authenticated users' browsers when they view affected pages. This vulnerability falls under CWE-79 which specifically addresses cross-site scripting vulnerabilities where insufficient input validation or output encoding allows attackers to inject malicious scripts into web applications. The issue is particularly concerning as it leverages the trust relationship between users and the application, enabling attackers to execute code in the victim's browser with the privileges of the authenticated user.
The technical exploitation of this vulnerability requires an attacker to first gain access to a GitLab instance with administrative or configuration privileges, or to manipulate existing integration settings that are accessible to unauthenticated users. Once the malicious javascript payload is injected into the Jira integration configuration, it becomes persistent and executes whenever users navigate to affected pages or interact with the integration interface. The vulnerability demonstrates a failure in input validation and output encoding practices, which are fundamental security controls recommended by the OWASP Top Ten and the CWE standard. The attack surface is expanded through the integration configuration system which typically accepts various parameters including URLs, API keys, and other configuration values that are not properly escaped or validated before being rendered in the user interface.
The operational impact of CVE-2023-6033 extends beyond simple script execution as it can lead to full account compromise, data exfiltration, and persistent access to the GitLab instance. An attacker could potentially steal session cookies, modify project configurations, access sensitive repositories, or escalate privileges within the system. The vulnerability is particularly dangerous in enterprise environments where GitLab serves as a central collaboration platform for development teams, as it could enable attackers to gain access to source code repositories, CI/CD pipelines, and other critical infrastructure components. This flaw aligns with ATT&CK technique T1566 which covers social engineering tactics, specifically focusing on the execution of malicious code through web-based attacks. Organizations using GitLab versions affected by this vulnerability face significant risk of unauthorized access and potential data breaches.
Mitigation strategies for CVE-2023-6033 should include immediate patching of affected GitLab instances to versions 16.6.1, 16.5.3, or 16.4.3 respectively, depending on the current version in use. Administrators should also implement additional security controls such as input validation for integration configuration parameters, regular monitoring of configuration changes, and restriction of access to integration settings to privileged users only. The vulnerability highlights the importance of proper output encoding and input validation practices, which are core requirements of the OWASP Secure Coding Practices and the CWE guidelines for preventing XSS vulnerabilities. Organizations should also consider implementing web application firewalls, content security policies, and regular security assessments to identify similar weaknesses in their GitLab deployments. Additionally, user education on recognizing suspicious integration configurations and monitoring for unusual system behavior can provide additional layers of defense against exploitation attempts.