CVE-2018-14605 in Community Edition
Summary
by MITRE
An issue was discovered in GitLab Community and Enterprise Edition before 10.8.7, 11.0.x before 11.0.5, and 11.1.x before 11.1.2. XSS can occur in the branch name during a Web IDE file commit.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 04/27/2023
This vulnerability resides in the GitLab web interface where user-supplied branch names are not properly sanitized before being rendered in the Web IDE file commit process. The issue affects multiple versions of GitLab Community and Enterprise Edition, specifically targeting releases prior to 10.8.7, 11.0.5, and 11.1.2 respectively. The flaw represents a classic cross-site scripting vulnerability that allows attackers to inject malicious scripts into branch names, which then execute in the context of other users who view these branch names within the Web IDE interface.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding practices within GitLab's Web IDE component. When users create or modify branches through the web interface, the branch name is stored in the system and subsequently displayed in various UI elements without proper sanitization of potentially malicious content. This occurs during the file commit process where branch names are rendered in HTML contexts, creating an opportunity for attackers to embed script tags or other malicious code within branch names that get executed when other users interact with the Web IDE.
The operational impact of this vulnerability is significant as it enables attackers to execute arbitrary JavaScript code in the context of authenticated users' sessions within GitLab. This could allow for session hijacking, data exfiltration, or the execution of malicious commands on behalf of other users. Attackers could craft branch names containing malicious payloads that would execute whenever legitimate users view the branch names in the Web IDE, potentially compromising the entire GitLab instance if users have elevated privileges. The vulnerability particularly affects collaborative development environments where multiple users interact with the same repositories and branch names.
Mitigation strategies should focus on implementing proper input validation and output encoding for all user-supplied content within the Web IDE interface. Organizations should immediately upgrade to patched versions of GitLab that address this vulnerability, specifically versions 10.8.7, 11.0.5, and 11.1.2 or later. The fix typically involves sanitizing branch names and other user inputs before rendering them in HTML contexts, implementing proper content security policies, and ensuring that all user-generated content undergoes proper validation before being stored or displayed. This vulnerability aligns with CWE-79 which describes cross-site scripting flaws, and represents a typical attack vector categorized under the ATT&CK technique T1059.007 for scripting languages, specifically targeting web-based applications through client-side code execution.