CVE-2017-20118 in Server
Summary
by MITRE • 06/29/2022
A vulnerability was found in TrueConf Server 4.3.7. It has been rated as problematic. Affected by this issue is some unknown functionality of the file /admin/conferences/list/. The manipulation of the argument domxss leads to basic cross site scripting (DOM). The attack may be launched remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 11/12/2022
The vulnerability identified as CVE-2017-20118 represents a significant security weakness in TrueConf Server version 4.3.7 that falls under the category of DOM-based cross-site scripting attacks. This issue manifests within the administrative interface of the conferencing platform, specifically in the /admin/conferences/list/ endpoint where user input is improperly handled. The vulnerability stems from inadequate sanitization of the domxss parameter, which allows malicious actors to inject malicious scripts into the browser environment through the DOM manipulation mechanism.
The technical flaw operates by exploiting the server's failure to properly validate and sanitize input parameters before processing them within the browser's Document Object Model. When a user interacts with the affected administrative interface and provides malicious input through the domxss argument, the server fails to adequately filter or escape the data before it gets executed in the client-side context. This creates an environment where attackers can execute arbitrary JavaScript code within the victim's browser session, potentially leading to session hijacking, credential theft, or further exploitation of the compromised system. The vulnerability is classified as a DOM-based XSS (CWE-79) attack because the malicious script is executed in the client's browser rather than being stored on the server.
The operational impact of this vulnerability is substantial as it enables remote code execution within the context of authenticated administrative sessions. An attacker who successfully exploits this vulnerability can gain unauthorized access to the conference management functionality, potentially modifying or deleting conference data, manipulating user accounts, or accessing sensitive information. The fact that this vulnerability has been publicly disclosed and the exploit is available increases the risk significantly, as it removes the requirement for advanced exploitation techniques and makes the attack accessible to threat actors with varying skill levels. The administrative nature of the affected endpoint means that successful exploitation could lead to complete compromise of the conferencing system and potential lateral movement within the network.
Mitigation strategies should focus on implementing robust input validation and output encoding mechanisms throughout the application's codebase, particularly in the administrative interfaces. The immediate solution involves sanitizing all user-provided input parameters, including the domxss argument, through proper escaping and validation techniques before any processing occurs. Implementing Content Security Policy headers can provide an additional layer of protection by restricting the sources from which scripts can be loaded and executed. Regular security assessments and code reviews should be conducted to identify similar vulnerabilities in other parts of the application. Organizations should also consider implementing web application firewalls to detect and block malicious requests targeting known vulnerable parameters. This vulnerability demonstrates the critical importance of addressing client-side security concerns and highlights the need for comprehensive security testing that includes both server-side and client-side validation mechanisms. The issue aligns with ATT&CK technique T1059.007 for script injection and T1566 for credential access, making it a significant threat vector in the context of enterprise security.