CVE-2021-20691 in Yomi-Search
Summary
by MITRE • 04/07/2021
Cross-site scripting vulnerability in Yomi-Search Ver4.22 allows remote attackers to inject an arbitrary script via unspecified vectors.
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Analysis
by VulDB Data Team • 04/11/2021
The CVE-2021-20691 vulnerability represents a critical cross-site scripting flaw discovered in Yomi-Search version 4.22, a web-based search application that processes user input through various interface elements. This vulnerability falls under the category of insecure input handling and represents a significant security risk for any organization relying on the application for data retrieval and search functionality. The vulnerability allows remote attackers to execute malicious scripts within the context of a victim's browser session, potentially leading to unauthorized access to sensitive information, session hijacking, or further exploitation of the affected system.
The technical nature of this vulnerability stems from insufficient input validation and output encoding mechanisms within the Yomi-Search application. Attackers can exploit unspecified vectors to inject malicious JavaScript code into the application's response, which then executes in the victim's browser when the page is rendered. This flaw typically occurs when user-supplied data is not properly sanitized before being incorporated into dynamic web content. The vulnerability is classified as a CWE-79 - Cross-site Scripting attack, which is a common weakness in web applications where user input is not adequately validated or escaped before being rendered to end users. The attack vector allows for arbitrary script injection, making it particularly dangerous as attackers can craft payloads that bypass standard security measures and execute with the privileges of the affected user.
The operational impact of CVE-2021-20691 extends beyond simple data theft or session manipulation, as it provides attackers with a potential foothold for more sophisticated attacks within the network environment. When exploited, this vulnerability can enable attackers to perform actions such as stealing session cookies, redirecting users to malicious websites, defacing web pages, or even executing arbitrary commands on the affected system. The remote nature of the attack means that exploitation can occur from anywhere on the internet without requiring physical access to the network. This vulnerability aligns with ATT&CK technique T1566.001 - Phishing: Spearphishing Attachment, as attackers can craft malicious payloads that appear legitimate to users, leveraging the search application's interface to deliver their payloads. Organizations using Yomi-Search may experience unauthorized data access, potential compliance violations, and reputational damage if this vulnerability is exploited.
Mitigation strategies for CVE-2021-20691 should include immediate application of vendor patches or updates to address the identified XSS vulnerability. Organizations should implement comprehensive input validation mechanisms that sanitize all user-supplied data before processing, employ proper output encoding techniques for dynamic content, and utilize Content Security Policy (CSP) headers to prevent unauthorized script execution. Additionally, regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other applications within the organization's infrastructure. The implementation of web application firewalls and security monitoring solutions can provide additional layers of protection against exploitation attempts. Organizations should also establish secure coding practices and conduct regular security training for developers to prevent similar vulnerabilities from being introduced during the software development lifecycle, ensuring compliance with industry standards such as OWASP Top Ten and NIST cybersecurity frameworks.