CVE-2023-34089 in Decidim
Summary
by MITRE • 07/11/2023
Decidim is a participatory democracy framework, written in Ruby on Rails, originally developed for the Barcelona City government online and offline participation website. The processes filter feature is susceptible to Cross-site scripting. This allows a remote attacker to execute JavaScript code in the context of a currently logged-in user. An attacker could use this vulnerability to make other users endorse or support proposals they have no intention of supporting or endorsing. The problem was patched in version 0.27.3 and 0.26.6.
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Analysis
by VulDB Data Team • 07/30/2023
CVE-2023-34089 represents a cross-site scripting vulnerability within the Decidim participatory democracy framework, a Ruby on Rails application designed for citizen engagement and democratic processes. This vulnerability exists in the processes filter feature, which allows remote attackers to inject malicious JavaScript code into the application's response. The flaw specifically enables attackers to execute arbitrary JavaScript within the context of a currently authenticated user session, leveraging the trust relationship between the user and the application. The vulnerability stems from insufficient input sanitization and output encoding in the filter functionality, creating a path for malicious payloads to be executed when processed by the web application. This type of vulnerability is categorized as CWE-79, which represents Cross-site Scripting, and aligns with ATT&CK technique T1566.001 for initial access through malicious web content.
The operational impact of this vulnerability extends beyond simple code execution, as it enables attackers to manipulate the participatory democracy process itself. An attacker could craft malicious filter inputs that, when processed, would cause authenticated users to unknowingly endorse or support proposals they never intended to support. This compromises the integrity of the democratic process by allowing manipulation of user intentions and votes. The vulnerability is particularly concerning for a platform designed for civic participation, as it undermines the fundamental principles of voluntary and informed consent that are essential to democratic engagement. The attack requires only that a victim navigate to a page containing the malicious filter input, making it particularly dangerous as it can be exploited through various vectors including social engineering, compromised third-party content, or by manipulating existing user-generated content.
The vulnerability was addressed in Decidim versions 0.27.3 and 0.26.6, which implemented proper input validation and output encoding mechanisms to prevent malicious script execution. Organizations using Decidim should immediately upgrade to these patched versions to mitigate the risk of exploitation. Security measures should include comprehensive input validation for all user-supplied data in filter and search functionalities, implementation of proper output encoding for dynamic content, and regular security testing of web application components. The fix demonstrates the importance of secure coding practices in web applications, particularly those handling sensitive user data and facilitating democratic processes. Organizations should also implement additional monitoring for suspicious user activities and consider network-based intrusion detection systems to identify potential exploitation attempts. The vulnerability highlights the need for continuous security assessment of web applications, especially those serving critical civic functions where the integrity of user interactions is paramount to maintaining public trust in digital democratic platforms.