Overview
A crucial vulnerability, designated as CVE-2025-4278, has been detected in GitLab CE/EE that affects all versions commencing with 18.0 and prior to 18.0.2. This vulnerability arises due to an HTML injection in the new search page under specific circumstances and could potentially lead to account takeover. As GitLab is a widely adopted platform for project planning, source code management, and CI/CD, such a vulnerability poses a significant threat to millions of users worldwide, affecting their data integrity and confidentiality.
Vulnerability Summary
CVE ID: CVE-2025-4278
Severity: High (8.7 CVSS Score)
Attack Vector: Network
Privileges Required: None
User Interaction: Required
Impact: Account takeover leading to potential system compromise or data leakage
Affected Products
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Product | Affected Versions
GitLab CE | 18.0 to 18.0.1
GitLab EE | 18.0 to 18.0.1
How the Exploit Works
The vulnerability works by exploiting the HTML injection flaw in GitLab’s new search page. An attacker can craft malicious HTML content and encode it in such a way that it is interpreted and rendered by the GitLab server. This can lead to the execution of arbitrary JavaScript code within the victim’s browser in the context of the affected site, thus potentially leading to account takeover.
Conceptual Example Code
A conceptual example of how this vulnerability might be exploited is shown below:
POST /search HTTP/1.1
Host: gitlab.example.com
Content-Type: application/x-www-form-urlencoded
query=<img src=x onerror=alert('Account compromised')>In this example, the attacker injects a malicious HTML tag into the search query. When this query is rendered by the victim’s browser, the `onerror` JavaScript event is triggered, executing the attacker’s arbitrary script. Depending on the complexity of the script, this could lead to session hijacking, account takeover, or even system compromise.
Please note that this is a conceptual example and real-world exploits may be more complex and sophisticated.
Mitigation and Fixes
Users are advised to immediately update their GitLab CE/EE installations to version 18.0.2 or later which contains the patch for this vulnerability. If immediate application of the vendor patch is not possible, using a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can serve as a temporary mitigation measure.
Remember, staying updated on the latest software versions and implementing recommended security measures is the best defense against such vulnerabilities.