CVE-2023-0300 in alf.io
Summary
by MITRE • 01/14/2023
Cross-site Scripting (XSS) - Reflected in GitHub repository alfio-event/alf.io prior to 2.0-M4-2301.
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Analysis
by VulDB Data Team • 07/07/2025
The vulnerability identified as CVE-2023-0300 represents a reflected cross-site scripting flaw within the alf.io event management platform, specifically affecting versions prior to 2.0-M4-2301. This issue resides in the GitHub repository alfio-event/alf.io and demonstrates a classic web application security weakness that can be exploited by malicious actors to inject client-side scripts into web pages viewed by other users. The vulnerability occurs when user-supplied input is not properly sanitized before being reflected back in the application's response, creating an avenue for attackers to execute arbitrary JavaScript code within the context of a victim's browser session.
The technical implementation of this reflected XSS vulnerability stems from insufficient input validation and output encoding mechanisms within the application's web framework. When users interact with the platform and provide data through various input fields, parameters, or query strings, the application fails to adequately sanitize this data before incorporating it into dynamic web responses. This flaw allows attackers to craft malicious payloads that, when executed, can steal session cookies, redirect users to malicious sites, or perform actions on behalf of authenticated users. The reflected nature of this vulnerability means that the malicious script is reflected off the web server and executed in the victim's browser, making it particularly dangerous as it requires no persistent storage of malicious code within the application itself.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to compromise user sessions and potentially escalate privileges within the application. Security researchers have classified this vulnerability under CWE-79 which specifically addresses Cross-site Scripting flaws in web applications, and it aligns with ATT&CK technique T1531 which covers "Run-time Application Proxy Execution". The consequences can range from unauthorized data access and session hijacking to more severe impacts such as privilege escalation or data exfiltration. Given that alf.io is an event management platform, attackers could potentially access sensitive event information, user registration data, or payment details, making this vulnerability particularly concerning for organizations relying on the platform for managing public events and collecting user information.
Mitigation strategies for CVE-2023-0300 require immediate implementation of proper input validation and output encoding mechanisms throughout the application. Organizations should implement Content Security Policy headers to limit script execution and ensure all user-supplied input undergoes strict sanitization before being processed or displayed. The recommended solution involves upgrading to version 2.0-M4-2301 or later, which contains the necessary patches to address the XSS vulnerability. Additionally, developers should adopt secure coding practices including the use of parameterized queries, proper HTML encoding of output, and comprehensive input validation to prevent similar issues in future development cycles. Security teams should also conduct regular vulnerability assessments and implement automated scanning tools to identify and remediate similar XSS vulnerabilities across their web applications, as this type of flaw remains one of the most prevalent security concerns in modern web environments.