CVE-2021-40922 in bugs
Summary
by MITRE • 10/02/2021
Cross-site scripting (XSS) vulnerability in install/index.php in bugs 1.8 and below version allows remote attackers to inject arbitrary web script or HTML via the last_name parameter.
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Analysis
by VulDB Data Team • 10/08/2021
The cross-site scripting vulnerability identified as CVE-2021-40922 affects the bugs application version 1.8 and earlier, specifically within the install/index.php file. This vulnerability represents a critical security flaw that enables remote attackers to execute malicious scripts in the context of affected users' browsers. The vulnerability manifests through the last_name parameter, which is processed without adequate input validation or output sanitization, creating an avenue for attackers to inject arbitrary web scripts or HTML content into the application's installation interface.
This XSS vulnerability falls under CWE-79, which categorizes it as a classic cross-site scripting flaw where the application fails to properly sanitize user input before incorporating it into dynamically generated web pages. The attack vector is particularly concerning because it targets the installation script, which typically operates with elevated privileges and may be accessible to unauthorized users during the initial setup phase of the application. The last_name parameter serves as the injection point, allowing attackers to craft malicious payloads that can execute in the victim's browser when the page is rendered.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform session hijacking, steal sensitive information, redirect users to malicious sites, or manipulate the application's behavior. During the installation process, attackers could inject scripts that capture user credentials, modify installation parameters, or even establish persistent backdoors within the application environment. The vulnerability's severity is amplified because installation scripts are often less protected than regular application components and may be accessible to users who should not have administrative capabilities.
Security practitioners should implement multiple layers of defense to mitigate this vulnerability. Input validation and output encoding represent the primary mitigation strategies, requiring that all user-supplied data be properly sanitized before being processed or displayed. The application should employ strict parameter validation for the last_name field and implement proper HTML escaping when rendering user input in the installation interface. Additionally, implementing content security policies and using secure coding practices such as parameterized queries and input sanitization frameworks can significantly reduce the risk of exploitation. This vulnerability aligns with ATT&CK technique T1203, which covers "Exploitation for Client Execution" and demonstrates how attackers can leverage web application vulnerabilities to execute malicious code in user browsers, potentially leading to further compromise of the affected systems and their associated networks.