CVE-2018-13339 in Angular Redactor
Summary
by MITRE
Imperavi Redactor 3 in Angular Redactor 1.1.6, when HTML content mode is used, allows stored XSS, as demonstrated by an onerror attribute of an IMG element, a related issue to CVE-2018-7035.
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Analysis
by VulDB Data Team • 04/03/2023
The vulnerability CVE-2018-13339 represents a critical stored cross-site scripting flaw in Imperavi Redactor 3 version 1.1.6 when operating in HTML content mode. This vulnerability arises from insufficient input sanitization and validation mechanisms within the rich text editor component, creating an exploitable entry point for malicious actors to inject persistent malicious code into web applications that utilize this editor. The flaw specifically manifests when users interact with HTML content mode, where the editor fails to properly sanitize user-supplied HTML input, particularly attributes and elements that could be leveraged for malicious purposes.
The technical implementation of this vulnerability allows attackers to inject malicious code through the onerror attribute of IMG elements, which is a well-documented XSS vector that exploits how browsers handle broken image loading scenarios. When an image fails to load, the browser triggers the onerror event handler, providing a legitimate execution context for JavaScript code injection. This particular attack vector is significant because it leverages browser behavior rather than requiring complex exploit chains, making it particularly dangerous for applications that allow user-generated content processing. The vulnerability is classified under CWE-79 as a failure to sanitize user input, specifically manifesting as a stored XSS condition where malicious payloads persist in the application's database and execute against unsuspecting users.
The operational impact of this vulnerability extends beyond simple code execution, as it enables attackers to perform a wide range of malicious activities including session hijacking, credential theft, data exfiltration, and redirection to malicious domains. When exploited successfully, the vulnerability can compromise user sessions and potentially provide attackers with elevated privileges within the application context. The stored nature of this XSS vulnerability means that once the malicious payload is injected, it will execute automatically whenever any user accesses the affected content, making it particularly dangerous for applications with multiple users or public-facing content management systems. This vulnerability directly aligns with ATT&CK technique T1059.007 for JavaScript execution and T1531 for credential access through session manipulation.
Mitigation strategies for CVE-2018-13339 should focus on immediate patching of the Imperavi Redactor component to the latest secure version that addresses the input sanitization deficiencies. Organizations should implement comprehensive content security policies that restrict the execution of inline scripts and limit the attributes that can be used in HTML content. Input validation and output encoding mechanisms must be strengthened to ensure that all user-supplied HTML content undergoes rigorous sanitization before being stored or rendered. Additionally, implementing web application firewalls with XSS detection capabilities and regular security scanning of web applications can help identify and prevent exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date third-party libraries and implementing proper security controls around user-generated content processing, as outlined in OWASP Top 10 2017 category A03: Injection and the security principles defined in NIST SP 800-160 for secure software development practices.