CVE-2021-45843 in glFusion
Summary
by MITRE • 09/29/2022
glFusion CMS v1.7.9 is affected by a reflected Cross Site Scripting (XSS) vulnerability. The value of the title request parameter is copied into the value of an HTML tag attribute which is encapsulated in double quotation marks. This input was echoed unmodified in the application's response.
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Analysis
by VulDB Data Team • 10/25/2022
The vulnerability identified as CVE-2021-45843 affects glFusion CMS version 1.7.9 and represents a reflected cross site scripting flaw that poses significant security risks to web applications. This type of vulnerability falls under the Common Weakness Enumeration category CWE-79 which specifically addresses Cross Site Scripting conditions where input data is not properly sanitized before being rendered in web responses. The flaw occurs when user-supplied data from the title request parameter is directly incorporated into HTML attributes without appropriate sanitization or encoding measures.
The technical implementation of this vulnerability involves the application's handling of user input within HTML contexts. When a user submits a request containing a malicious title parameter, the CMS processes this input by copying it directly into an HTML tag attribute that is enclosed in double quotation marks. This creates an opportunity for attackers to inject malicious scripts that will execute in the context of other users' browsers. The vulnerability is classified as reflected because the malicious payload is embedded in the request itself and reflected back to the user's browser without any server-side storage or processing of the input.
The operational impact of this vulnerability extends beyond simple script execution as it can enable attackers to perform various malicious activities including session hijacking, credential theft, and redirection to malicious websites. According to the MITRE ATT&CK framework, this vulnerability maps to technique T1531 which involves the use of malicious scripts to compromise user sessions and gain unauthorized access to sensitive information. The reflected nature of the XSS allows attackers to craft specific payloads that will be executed when victims click on malicious links or visit compromised pages, making this a particularly dangerous vulnerability for content management systems that handle user-generated content.
The exploitation of this vulnerability requires minimal technical expertise and can be carried out through simple web-based attacks. Attackers can construct malicious URLs containing encoded script payloads that, when visited by unsuspecting users, will execute in their browsers. The lack of proper input validation and sanitization in the CMS application creates an environment where malicious scripts can persistently target users who interact with the affected functionality. This vulnerability particularly impacts web applications that rely on user input for dynamic content generation, as it demonstrates how insufficient data validation can create persistent security weaknesses.
Mitigation strategies for CVE-2021-45843 should focus on implementing proper input sanitization and output encoding mechanisms throughout the application. The recommended approach involves applying context-specific encoding to all user-supplied data before rendering it in HTML contexts, particularly when the data is placed within attribute values. Organizations should implement Content Security Policy headers to limit script execution and prevent unauthorized code injection. Additionally, the CMS should be updated to a patched version that includes proper input validation routines and ensures that all user-provided data is sanitized before being incorporated into dynamic HTML elements. Regular security audits and automated vulnerability scanning should be implemented to identify similar issues in other application components and maintain overall security posture against evolving threats.