CVE-2019-11084 in GAuth
Summary
by MITRE
GAuth 0.9.9 beta has stored XSS that shows a popup repeatedly and discloses cookies.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/04/2023
The vulnerability identified as CVE-2019-11084 affects GAuth version 0.9.9 beta and represents a critical stored cross-site scripting flaw that enables persistent malicious code execution within the application's user interface. This vulnerability specifically manifests through a popup mechanism that repeatedly displays to users, creating a persistent threat vector that can be exploited to steal sensitive session information. The flaw allows attackers to inject malicious scripts into stored data that gets rendered back to users, creating a dangerous feedback loop where the malicious content continuously reappears. The vulnerability's design enables the disclosure of cookies, which contain critical session tokens and authentication data that can be harvested by attackers to impersonate legitimate users within the application environment.
The technical implementation of this stored XSS vulnerability stems from inadequate input validation and output sanitization within the GAuth application's data handling processes. When users interact with the application and their input is stored without proper sanitization, malicious scripts can be embedded within the data that gets subsequently displayed to other users. The popup mechanism serves as a delivery vector for the malicious JavaScript code, which can be crafted to execute in the context of the victim's browser session. This particular implementation follows the typical stored XSS attack pattern where the payload is stored on the server and executed when other users view the affected content, making it particularly dangerous as it affects multiple users over time. The vulnerability operates under CWE-79 which specifically addresses cross-site scripting flaws in application input handling and output rendering processes.
The operational impact of CVE-2019-11084 extends beyond simple data theft, as it creates a persistent threat that can be leveraged for account takeover, session hijacking, and further reconnaissance activities within the compromised application. The repeated popup behavior ensures that the malicious payload maintains visibility to users, increasing the likelihood of successful exploitation and making the vulnerability more difficult to detect and mitigate. Attackers can use this vulnerability to harvest authentication cookies, session tokens, and potentially sensitive user information that may be present in the application's context. The continuous nature of the popup mechanism also provides attackers with multiple opportunities to execute their payload and gather intelligence about user behavior and application functionality. This vulnerability directly enables techniques described in the ATT&CK framework under the credential access and persistence domains, particularly targeting the use of web-based attacks to compromise user sessions and maintain long-term access to the application environment.
Mitigation strategies for this stored XSS vulnerability must address both the immediate threat and prevent future occurrences through comprehensive input validation and output sanitization measures. Organizations should implement strict sanitization of all user input before storage, utilizing context-appropriate encoding mechanisms such as HTML entity encoding for web content rendering. The application should employ Content Security Policy headers to limit the execution of inline scripts and restrict the sources from which scripts can be loaded. Regular security testing including automated scanning and manual penetration testing should be conducted to identify and remediate similar vulnerabilities in the application's codebase. Additionally, implementing proper access controls and monitoring for unusual user behavior patterns can help detect exploitation attempts. The vulnerability demonstrates the critical importance of addressing input validation at all layers of application development and aligns with security best practices outlined in OWASP Top Ten and NIST cybersecurity frameworks for preventing web application vulnerabilities that can lead to session hijacking and unauthorized access to user accounts.