CVE-2019-18454 in Community Edition
Summary
by MITRE
An issue was discovered in GitLab Community and Enterprise Edition 10.5 through 12.4 in link validation for RDoc wiki pages feature. It has XSS.
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Analysis
by VulDB Data Team • 02/28/2024
The vulnerability CVE-2019-18454 represents a cross-site scripting flaw in GitLab's RDoc wiki pages feature that affects versions 10.5 through 12.4 of both Community and Enterprise editions. This security issue stems from inadequate input validation mechanisms that fail to properly sanitize user-provided content when rendering wiki pages. The vulnerability specifically impacts the RDoc markup processing functionality where links are validated and displayed within wiki documentation, creating an opportunity for malicious actors to inject malicious scripts into the application's rendering pipeline.
The technical implementation of this vulnerability resides in GitLab's wiki page rendering engine where RDoc formatted links are processed without sufficient sanitization of user inputs. When users create wiki pages containing links with malicious payloads, the application fails to properly escape or filter special characters that could be interpreted as executable script code. This weakness allows attackers to craft specially formatted links that, when rendered by the wiki page viewer, execute arbitrary JavaScript code within the context of other users' browsers. The flaw operates under CWE-79 which categorizes cross-site scripting vulnerabilities as a result of insufficient input validation and output encoding.
The operational impact of this vulnerability extends beyond simple script execution as it enables attackers to perform session hijacking, data theft, and privilege escalation within the GitLab environment. An attacker could craft malicious wiki pages that, when viewed by authenticated users, would execute scripts to steal session cookies or redirect users to malicious sites. The vulnerability affects all users within the GitLab instance who have access to create or modify wiki pages, potentially compromising the entire user base that interacts with these documentation features. This issue particularly threatens organizations that rely heavily on wiki-based documentation systems where multiple users contribute content and where the wiki serves as a central knowledge repository.
Organizations should implement immediate mitigations including updating to GitLab versions 12.5 or later where the vulnerability has been patched, implementing web application firewalls to detect and block suspicious link patterns, and conducting thorough security reviews of existing wiki content to identify potential malicious entries. The remediation process should also include user education about the risks of creating untrusted wiki content and implementing strict access controls for wiki page creation. Security teams should monitor for exploitation attempts through log analysis and consider implementing content security policies to prevent script execution within the wiki rendering context. This vulnerability aligns with ATT&CK technique T1566 which covers social engineering tactics involving malicious content delivery, specifically targeting the wiki documentation environment as a vector for user compromise.