CVE-2017-8778 in GitLab
Summary
by MITRE
GitLab before 8.14.9, 8.15.x before 8.15.6, and 8.16.x before 8.16.5 has XSS via a SCRIPT element in an issue attachment or avatar that is an SVG document.
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Analysis
by VulDB Data Team • 12/06/2022
The vulnerability identified as CVE-2017-8778 represents a cross-site scripting weakness in GitLab versions prior to specific patches, affecting the software's handling of SVG document attachments and avatars. This issue stems from inadequate input validation and sanitization mechanisms within the platform's file processing pipeline, particularly when dealing with vector graphics format files that contain embedded script elements. The vulnerability specifically targets the rendering of SVG documents which can contain executable script code within SCRIPT elements, creating a potential attack vector for malicious actors to inject harmful content into the GitLab environment.
The technical flaw manifests when GitLab processes SVG files that contain SCRIPT elements within their document structure, failing to properly sanitize or escape these potentially dangerous components before rendering them in the user interface. This oversight allows attackers to upload specially crafted SVG files that contain embedded JavaScript code, which executes in the context of other users' browsers when the malicious file is viewed within the GitLab application. The vulnerability exists at the intersection of web application security and file processing validation, where SVG files are treated as trusted content without proper security checks that would normally be applied to user-uploaded files.
Operationally, this vulnerability presents significant risks to GitLab users and organizations relying on the platform for code collaboration and project management. Attackers can exploit this weakness to execute malicious scripts in the context of other users, potentially leading to session hijacking, data exfiltration, or privilege escalation within the GitLab environment. The impact extends beyond simple script execution as it can enable attackers to perform actions such as accessing private repositories, modifying project content, or stealing authentication tokens from authenticated users. The vulnerability affects both issue attachments and user avatars, providing multiple attack surfaces for exploitation, and can be particularly dangerous in enterprise environments where GitLab serves as a central collaboration platform.
Mitigation strategies for CVE-2017-8778 should prioritize immediate patching of affected GitLab versions to the recommended secure releases, specifically upgrading to GitLab 8.14.9, 8.15.6, or 8.16.5 respectively. Organizations should implement additional defensive measures including strict file type validation and sanitization of uploaded SVG content, implementing content security policies that restrict script execution in user-uploaded files, and conducting regular security audits of file processing components. The vulnerability aligns with CWE-79, which describes cross-site scripting flaws, and maps to ATT&CK technique T1059.007 for script injection, emphasizing the need for comprehensive input validation and output encoding mechanisms to prevent malicious code execution in web applications.