CVE-2017-1000223 in Revolution
Summary
by MITRE
A stored web content injection vulnerability (WCI, a.k.a XSS) is present in MODX Revolution CMS version 2.5.6 and earlier. An authenticated user with permissions to edit users can save malicious JavaScript as a User Group name and potentially take control over victims' accounts. This can lead to an escalation of privileges providing complete administrative control over the CMS.
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Analysis
by VulDB Data Team • 12/08/2019
The vulnerability identified as CVE-2017-1000223 represents a critical stored cross-site scripting flaw within MODX Revolution CMS versions 2.5.6 and earlier. This weakness falls under the category of web content injection vulnerabilities where malicious code can be persistently stored and subsequently executed within the application's interface. The vulnerability specifically targets the User Group management functionality, which allows authenticated users with appropriate permissions to manipulate user access controls. The flaw demonstrates how seemingly benign administrative features can become attack vectors when proper input sanitization and output encoding mechanisms are absent from the application's security architecture.
The technical implementation of this vulnerability stems from inadequate validation and sanitization of user-supplied input within the User Group naming field. When an authenticated attacker with user editing permissions creates or modifies a User Group, they can inject malicious javascript code into the group name field. This code then gets stored in the database and subsequently rendered in the user interface without proper sanitization or encoding. The vulnerability is classified as a stored XSS (CW 79) as the malicious payload persists in the application's data store and executes whenever the affected page is loaded. This type of vulnerability is particularly dangerous because it can be triggered automatically when other users view the compromised interface elements without any additional interaction required from the victim.
The operational impact of this vulnerability extends beyond simple script execution to represent a complete privilege escalation vector that can lead to full administrative control over the CMS. An attacker who successfully exploits this vulnerability can potentially hijack user sessions, modify or delete content, create new administrative accounts, and access sensitive system information. The attack chain typically begins with gaining access to a legitimate user account with sufficient permissions to edit user groups, followed by the injection of malicious code that can then be leveraged to compromise other users within the system. This vulnerability directly maps to attack techniques described in the ATT&CK framework under the Privilege Escalation and Credential Access domains, specifically targeting the use of web application vulnerabilities to gain elevated system access.
Mitigation strategies for CVE-2017-1000223 require immediate attention through patch management and security hardening procedures. Organizations should prioritize upgrading to MODX Revolution version 2.5.7 or later, which includes proper input validation and output encoding fixes for this vulnerability. Additional defensive measures include implementing strict input validation at multiple layers of the application architecture, enforcing proper output encoding for all dynamic content, and establishing comprehensive monitoring for suspicious user group modifications. Security teams should also consider implementing web application firewalls to detect and block malicious input patterns, while conducting regular security assessments to identify similar vulnerabilities in other components of the CMS. The vulnerability highlights the importance of maintaining up-to-date security practices and demonstrates how even authenticated access can be leveraged to achieve unauthorized system control when proper security controls are absent from the application's codebase.