CVE-2017-0924 in Community Edition
Summary
by MITRE
Gitlab Community Edition version 10.2.4 is vulnerable to lack of input validation in the labels component resulting in persistent cross site scripting.
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Analysis
by VulDB Data Team • 01/15/2020
The vulnerability identified as CVE-2017-0924 affects Gitlab Community Edition version 10.2.4 and represents a critical security flaw in the application's input validation mechanisms. This issue specifically targets the labels component within the Gitlab platform, which is commonly used by development teams to categorize and organize issues, merge requests, and other project elements. The weakness stems from insufficient sanitization of user-provided data when processing label names and descriptions, creating an environment where malicious actors can inject harmful scripts that persist within the application's data store. The vulnerability is classified as a persistent cross site scripting flaw, meaning that the malicious code remains stored in the system and can be executed whenever users view affected labels, making it particularly dangerous for collaborative development environments where multiple team members interact with the same project data.
The technical implementation of this vulnerability allows attackers to exploit the lack of proper input validation by submitting specially crafted label data containing malicious javascript payloads. When other users view the affected labels within the Gitlab interface, the stored scripts execute in their browsers, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim. The flaw operates at the application layer and specifically affects how Gitlab processes user input for label attributes, which are fundamental components used in project management and issue tracking workflows. This vulnerability demonstrates a failure in the principle of least privilege and input sanitization, as the system should validate and sanitize all user-supplied data before storing it in the database. The attack vector is particularly concerning because it requires minimal privileges to exploit, as any user with access to create or modify labels can potentially introduce malicious code that affects all other users of the platform.
The operational impact of CVE-2017-0924 extends beyond simple script execution, as it can enable attackers to compromise entire development environments and steal sensitive project information. Organizations using Gitlab for version control and collaboration are at risk of having their source code repositories, issue tracking systems, and development workflows compromised. The persistent nature of the vulnerability means that even after initial exploitation, the malicious code continues to affect users until the affected labels are manually removed or the system is patched. This makes the vulnerability particularly dangerous in large organizations where multiple developers interact with the same repositories and project data. The attack can be executed through various means including creating malicious labels, modifying existing labels, or even through automated tools that systematically inject payloads into label fields. This vulnerability directly maps to CWE-79, which describes cross-site scripting flaws in software applications, and aligns with ATT&CK technique T1059.007 for script execution through web interfaces. The exploitation of this vulnerability can lead to complete compromise of development environments, unauthorized code commits, and potential data exfiltration from sensitive projects.
Mitigation strategies for CVE-2017-0924 should focus on immediate patching of the affected Gitlab Community Edition version to the latest stable release that includes the necessary input validation fixes. Organizations should implement comprehensive input sanitization measures at the application level, including the removal of potentially dangerous characters and the use of proper HTML escaping for all user-provided data. Network-based mitigations such as web application firewalls can help detect and block malicious payloads, though these should not be considered as primary defenses. Regular security audits of label creation and modification processes should be implemented to identify and remove malicious entries. The affected systems should also implement proper access controls to limit label creation privileges to trusted users only, reducing the attack surface. Additionally, organizations should establish incident response procedures specifically designed to handle cross site scripting vulnerabilities, including regular monitoring of user activities and automated alerting for suspicious label modifications. Security teams should also consider implementing content security policies to prevent execution of unauthorized scripts even if the vulnerability is exploited, providing an additional layer of defense. The vulnerability underscores the importance of maintaining current software versions and implementing robust input validation as fundamental security practices in collaborative development platforms.