CVE-2018-19782 in FreshRSS
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in GET requests in FreshRSS 1.11.1 allow remote attackers to inject arbitrary web script or HTML via the (1) c parameter or (2) a parameter.
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Analysis
by VulDB Data Team • 07/03/2024
The vulnerability identified as CVE-2018-19782 represents a critical cross-site scripting flaw affecting FreshRSS version 1.11.1, a popular open-source RSS feed reader application. This vulnerability manifests in GET requests and provides remote attackers with the capability to inject malicious web scripts or HTML content directly into the application's response handling mechanisms. The flaw specifically impacts two parameters within the application's request processing pipeline, namely the 'c' parameter and the 'a' parameter, which are likely used for controlling application context and action routing respectively.
The technical nature of this vulnerability aligns with CWE-79, which defines cross-site scripting as a code injection attack that occurs when an application includes untrusted data in a web page without proper validation or escaping. In FreshRSS's case, the application fails to adequately sanitize input parameters received through GET requests, allowing attackers to inject malicious payloads that execute within the context of other users' browsers. The vulnerability's exploitation requires minimal privileges since it operates over standard HTTP GET requests, making it particularly dangerous as it can be triggered through simple URL manipulation without requiring authentication or specialized tools.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it provides attackers with the ability to establish persistent malicious presence within the application's user base. When users interact with compromised RSS feeds or navigate to affected pages, their browsers execute the injected scripts, potentially leading to session hijacking, credential theft, or redirection to malicious sites. The attack surface is particularly broad given that RSS readers are frequently used by individuals and organizations, making successful exploitation capable of affecting numerous end-users simultaneously. This vulnerability also aligns with ATT&CK technique T1566, which covers social engineering through malicious content delivery, as attackers can craft malicious RSS feed entries that exploit this vulnerability.
Mitigation strategies for CVE-2018-19782 must address both immediate remediation and long-term security hardening. The primary solution involves upgrading to a patched version of FreshRSS where input validation and output escaping have been properly implemented for the affected parameters. Organizations should also implement proper parameter sanitization at the application level, ensuring all GET request parameters undergo rigorous validation before being processed or displayed. Input validation should include strict whitelisting of acceptable parameter values and comprehensive output encoding for any user-supplied content. Additionally, implementing Content Security Policy headers can provide an additional layer of defense by restricting script execution within the application context. Security teams should also consider deploying web application firewalls to monitor and block suspicious request patterns that may indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper input validation and output escaping in web applications, particularly in software that processes user-generated content like RSS feeds, where the attack surface can be expanded through malicious feed entries.