CVE-2021-20752 in RSS Reader
Summary
by MITRE • 07/01/2021
Cross-site scripting vulnerability in IkaIka RSS Reader all versions allows a remote attacker to inject an arbitrary script via unspecified vectors.
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Analysis
by VulDB Data Team • 07/09/2021
The CVE-2021-20752 vulnerability represents a critical cross-site scripting flaw within the IkaIka RSS Reader application across all its versions. This vulnerability falls under the category of web application security flaws that enable malicious actors to execute unauthorized scripts in the context of a victim's browser session. The vulnerability is particularly concerning as it affects all versions of the application, indicating a fundamental flaw in the codebase that has not been addressed through version updates.
The technical nature of this XSS vulnerability stems from insufficient input validation and output encoding mechanisms within the RSS reader application. Attackers can exploit this weakness by crafting malicious payloads that are then executed when other users view the compromised content through the vulnerable application interface. The unspecified vectors suggest that multiple entry points within the application could be exploited, potentially including RSS feed parsing, user input fields, or parameter handling within the web interface itself. This broad attack surface increases the likelihood of successful exploitation across various operational scenarios.
From an operational impact perspective, this vulnerability creates significant security risks for organizations and individual users who rely on the IkaIka RSS Reader for content consumption. Remote attackers can leverage this flaw to steal session cookies, perform unauthorized actions on behalf of users, redirect victims to malicious websites, or even execute more sophisticated attacks such as credential theft or data exfiltration. The vulnerability essentially undermines the trust model of web applications by allowing untrusted content to execute arbitrary code within the user's browser context, which directly violates the principle of least privilege and secure coding practices.
The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in web applications, and represents a classic example of how inadequate sanitization of user-supplied data can lead to severe security consequences. From an ATT&CK framework perspective, this vulnerability maps to techniques such as T1566.001 (Phishing: Spearphishing Attachment) and T1059.001 (Command and Scripting Interpreter: PowerShell) when attackers leverage XSS to establish persistent access or escalate privileges through browser-based attacks. Organizations using this application face heightened risk of data breaches and compromised user accounts, particularly in environments where users regularly consume RSS feeds from untrusted sources.
Mitigation strategies should include immediate implementation of proper input validation and output encoding mechanisms throughout the application, specifically ensuring that all user-supplied data is properly sanitized before being rendered in web pages. The application should implement Content Security Policy headers to restrict script execution and employ proper escape sequences for all dynamic content. Security patches should be applied immediately to address this vulnerability, and organizations should consider implementing web application firewalls to detect and block potential exploitation attempts. Additionally, user education regarding the risks of consuming content from untrusted RSS sources remains crucial in reducing the overall attack surface and preventing successful exploitation of this XSS vulnerability.