CVE-2018-14850 in Tiki
Summary
by MITRE
Stored XSS vulnerabilities in Tiki before 18.2, 15.7 and 12.14 allow an authenticated user injecting JavaScript to gain administrator privileges if an administrator opens a wiki page and moves the mouse pointer over a modified link or thumb image.
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Analysis
by VulDB Data Team • 03/15/2020
This vulnerability represents a critical stored cross-site scripting flaw in the Tiki wiki platform that enables authenticated users to escalate their privileges through malicious JavaScript injection. The vulnerability affects multiple versions including Tiki 18.2, 15.7, and 12.14, indicating a persistent security weakness that has remained unaddressed across several release cycles. The flaw specifically manifests when administrators interact with modified content elements such as links or thumbnail images, creating a dangerous attack vector that leverages the administrator's elevated privileges to execute malicious code.
The technical implementation of this vulnerability involves the improper sanitization of user input within wiki page content storage mechanisms. When an authenticated attacker injects malicious JavaScript into wiki pages, the code persists in the database and executes when administrators view these pages. The trigger mechanism requires the administrator to move their mouse pointer over modified links or thumbnail images, which suggests that the vulnerability exploits event handlers or hover effects that execute JavaScript code. This behavior aligns with CWE-79, which describes cross-site scripting vulnerabilities resulting from insufficient input validation and output encoding. The attack requires minimal user interaction beyond the initial content injection, making it particularly dangerous as it can be concealed within seemingly benign wiki elements.
The operational impact of this vulnerability extends beyond simple XSS exploitation, as it provides attackers with the ability to escalate privileges to administrator level access. This privilege escalation occurs because the malicious JavaScript code executes within the context of the administrator's session, potentially allowing attackers to manipulate system settings, modify content, access sensitive data, or even compromise the entire platform. The vulnerability's reliance on administrator interaction creates a significant risk to organizations that maintain extensive wiki environments where administrative users frequently browse content. Attackers can craft malicious links or images that appear legitimate, making the attack difficult to detect and trace. This scenario represents a classic privilege escalation attack pattern that aligns with ATT&CK technique T1078.004, which covers valid accounts with elevated privileges being used for persistence and privilege escalation.
The security implications of this vulnerability highlight fundamental weaknesses in the Tiki platform's input validation and output encoding mechanisms. The fact that the attack requires only authenticated access demonstrates that the platform's security model is insufficiently protecting against malicious content injection from users with legitimate access rights. Organizations using affected Tiki versions face significant exposure risks, particularly in environments where multiple users contribute content or where administrators regularly interact with user-generated content. The vulnerability's exploitation requires minimal technical expertise, making it attractive to attackers who may not possess advanced penetration testing skills. Additionally, the persistent nature of stored XSS means that the malicious code remains active until the platform is patched, providing attackers with extended periods of potential access. Organizations should implement immediate mitigation strategies including applying the latest security patches, implementing content filtering mechanisms, and conducting comprehensive security assessments of their wiki environments. The vulnerability also underscores the importance of proper security testing and code review processes to identify and address such critical flaws before they can be exploited in production environments.