CVE-2019-7172 in ATutor
Summary
by MITRE
A stored-self XSS exists in ATutor through v2.2.4, allowing an attacker to execute HTML or JavaScript code in a vulnerable Real Name field to /mods/_core/users/admins/my_edit.php.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 07/04/2023
The vulnerability CVE-2019-7172 represents a stored cross-site scripting flaw within ATutor version 2.2.4 and earlier, specifically affecting the administration interface at the path /mods/_core/users/admins/my_edit.php. This issue arises from inadequate input validation and output sanitization mechanisms that fail to properly escape user-supplied data before rendering it within the web application's HTML context. The vulnerability is classified as a stored XSS attack because the malicious payload is permanently stored within the application's database and subsequently executed whenever the affected page is accessed by authenticated users with administrative privileges.
The technical exploitation of this vulnerability occurs through the Real Name field within the administrative user profile editing functionality. When an attacker successfully injects malicious JavaScript code into this field, the code becomes permanently stored in the database and executes in the context of any user who views the modified profile information. This stored payload can be triggered when administrators navigate to the user management interface or when the profile information is rendered in various administrative panels. The vulnerability demonstrates a critical flaw in the application's data handling processes, where user input is not properly sanitized or escaped before being incorporated into dynamic HTML output.
The operational impact of CVE-2019-7172 extends beyond simple script execution, as it provides attackers with the ability to perform session hijacking, steal administrative credentials, redirect users to malicious websites, or perform actions on behalf of the compromised administrator. This vulnerability directly violates security principles outlined in CWE-79 which addresses cross-site scripting flaws, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter. The attack surface is particularly concerning because it targets administrative interfaces, potentially allowing attackers to escalate privileges and gain full control over the ATutor learning management system. The stored nature of the vulnerability means that even after the initial injection, the malicious code continues to execute automatically whenever the affected page is accessed, creating a persistent threat vector.
Mitigation strategies for CVE-2019-7172 should focus on implementing comprehensive input validation and output encoding mechanisms throughout the application. The primary remediation involves sanitizing all user-supplied data, particularly in fields that are rendered within HTML contexts, through proper HTML entity encoding or the use of Content Security Policy headers. Organizations should implement strict input validation that rejects or removes potentially dangerous characters and patterns commonly associated with XSS attacks. Additionally, the application should employ proper output encoding techniques when rendering user data within HTML contexts, ensuring that any special characters are properly escaped. The vulnerability highlights the importance of following secure coding practices and implementing defense-in-depth strategies that include regular security code reviews, automated vulnerability scanning, and maintaining up-to-date software versions. Organizations should also consider implementing web application firewalls and monitoring mechanisms to detect and prevent exploitation attempts, while ensuring that administrative interfaces have additional security controls such as multi-factor authentication and IP whitelisting.