CVE-2018-14849 in Tiki
Summary
by MITRE
Tiki before 18.2, 15.7 and 12.14 has XSS via link attributes, related to lib/core/WikiParser/OutputLink.php and lib/parser/parserlib.php.
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Analysis
by VulDB Data Team • 03/15/2020
The vulnerability identified as CVE-2018-14849 represents a cross-site scripting flaw affecting Tiki wiki software versions prior to 18.2, 15.7, and 12.14. This issue resides within the wiki's link processing functionality and specifically involves the lib/core/WikiParser/OutputLink.php and lib/parser/parserlib.php files. The vulnerability stems from insufficient input validation and sanitization of link attributes, creating an avenue for malicious actors to inject arbitrary JavaScript code into the application's output. When users view pages containing specially crafted links, the malicious scripts execute in the context of other users' browsers, potentially leading to session hijacking, data theft, or further exploitation of the compromised systems.
The technical exploitation of this vulnerability occurs through the improper handling of link attributes within the wiki's parsing engine. The affected files fail to adequately sanitize user-provided attributes before rendering them in HTML output, allowing attackers to inject malicious content such as javascript:alert(1) or more sophisticated payload sequences. This weakness directly maps to CWE-79, which defines cross-site scripting as the failure to properly escape or validate user input before including it in web page output. The vulnerability is particularly concerning because it operates at the core parsing layer of the wiki system, meaning any content that gets processed through the link handling mechanisms could potentially become a vector for attack.
The operational impact of CVE-2018-14849 extends beyond simple script execution, as it provides attackers with the capability to manipulate user sessions and access sensitive data within the wiki environment. When exploited successfully, this vulnerability could allow unauthorized users to read, modify, or delete content across the affected wiki instances. The attack surface is broad since any wiki page that displays user-generated links or content could serve as an entry point. Security professionals should consider this vulnerability in the context of the ATT&CK framework under the T1059.007 technique for scripting languages, specifically targeting web-based applications. Organizations running vulnerable versions of Tiki should also be aware of potential credential theft, as the XSS could be used to capture login information or session cookies from authenticated users.
Mitigation strategies for CVE-2018-14849 should focus on immediate patching of affected Tiki installations to versions 18.2, 15.7, or 12.14 where the vulnerability has been addressed. Administrators should also implement comprehensive input validation and output encoding measures, particularly for link attributes and any user-supplied content that gets rendered in the application interface. The implementation of Content Security Policy headers can provide additional defense-in-depth against potential exploitation attempts. Organizations should conduct thorough security assessments of their wiki environments to identify any custom modifications or third-party extensions that might introduce similar vulnerabilities. Regular security monitoring and automated vulnerability scanning should be maintained to detect any potential re-introduction of similar flaws or new vulnerabilities in the system's codebase.