CVE-2018-7303 in Tiki
Summary
by MITRE
The Calendar component in Tiki 17.1 allows HTML injection.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 01/07/2020
The vulnerability identified as CVE-2018-7303 represents a critical HTML injection flaw within the Calendar component of Tiki 17.1 content management system. This security weakness resides in the application's handling of user-provided calendar event data, where insufficient input validation and output encoding mechanisms fail to properly sanitize malicious HTML content. The vulnerability stems from the component's inability to distinguish between legitimate user-generated content and potentially harmful script tags or HTML elements that could be embedded within calendar event descriptions, titles, or other editable fields. Attackers can exploit this flaw by submitting specially crafted HTML content through calendar event creation or modification interfaces, which then gets rendered on calendar pages without proper sanitization.
The technical nature of this vulnerability aligns with CWE-79, which categorizes HTML injection as a form of cross-site scripting vulnerability where untrusted data is directly included in web pages without proper encoding or validation. This particular implementation flaw allows threat actors to inject malicious scripts that can execute within the context of other users' browsers when they view affected calendar events. The vulnerability operates at the application layer where user input is processed and displayed, creating a persistent threat vector that can be exploited across multiple calendar events and potentially affect all users with access to the calendar component.
The operational impact of CVE-2018-7303 extends beyond simple data corruption or display issues, as it creates opportunities for more sophisticated attacks including session hijacking, credential theft, and redirection to malicious websites. When users interact with calendar events containing injected HTML content, their browsers execute the embedded scripts, potentially compromising their sessions or redirecting them to phishing sites. The vulnerability affects the confidentiality, integrity, and availability of the calendar component's data, as attackers can modify event displays, inject malicious code, or even redirect users to harmful destinations. Organizations using Tiki 17.1 are particularly vulnerable because the calendar component is often widely used for scheduling, collaboration, and information sharing, making it a prime target for exploitation.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input validation and output encoding mechanisms throughout the calendar component's data handling processes. Security measures must include sanitizing all user-provided content before storage and rendering, implementing proper HTML escaping for dynamic content, and applying the principle of least privilege to calendar event creation and modification functions. Organizations should also consider implementing content security policies to prevent execution of unauthorized scripts, regular security audits of web applications, and immediate patching of the Tiki 17.1 system to address the specific HTML injection vulnerability. Additionally, network monitoring and intrusion detection systems should be configured to detect suspicious calendar-related activities that might indicate exploitation attempts, while user training programs should emphasize the importance of not clicking on suspicious calendar events or attachments from untrusted sources. The remediation process should align with ATT&CK framework tactics related to defense evasion and command and control, ensuring that any mitigation measures do not inadvertently create new attack vectors while effectively addressing the core HTML injection weakness.