CVE-2017-20116 in Server
Summary
by MITRE • 06/29/2022
A vulnerability was found in TrueConf Server 4.3.7. It has been classified as problematic. Affected is an unknown function of the file /admin/group/list/. The manipulation of the argument checked_group_id leads to basic cross site scripting (Reflected). It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 03/24/2023
The vulnerability identified as CVE-2017-20116 represents a reflected cross site scripting flaw within TrueConf Server version 4.3.7, specifically affecting the administrative group listing functionality. This security weakness resides in the /admin/group/list/ endpoint where the checked_group_id parameter is improperly validated and sanitized, creating an avenue for malicious code injection. The vulnerability classification as problematic indicates a significant security risk that could compromise the integrity of the affected system and its users. The flaw manifests when the application fails to properly escape or validate user-supplied input before incorporating it into dynamically generated web content, allowing attackers to inject malicious scripts that execute in the context of other users' browsers.
The technical implementation of this vulnerability follows the typical pattern of reflected XSS attacks where malicious input is first received by the server through user interaction, then reflected back to the user's browser without proper sanitization. In this case, the checked_group_id argument serves as the injection vector, and when processed by the server-side application logic, it directly influences the output delivered to the user interface. The reflected nature of this vulnerability means that the malicious payload is not stored on the server but rather transmitted through a crafted URL or form submission that causes the server to reflect the malicious script back to the victim's browser. This attack vector requires user interaction to be effective, typically through phishing emails or social engineering tactics that prompt users to click malicious links.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the capability to hijack user sessions, steal sensitive information, and potentially escalate privileges within the compromised system. Since the vulnerability exists in the administrative interface, successful exploitation could allow attackers to gain unauthorized access to administrative functions and potentially compromise the entire TrueConf Server infrastructure. The remote exploitability of this vulnerability means that attackers do not require physical access to the network or system, making it particularly dangerous for organizations that maintain public-facing administrative interfaces. This vulnerability aligns with CWE-79 which specifically addresses cross site scripting flaws, and maps to ATT&CK technique T1566.001 for initial access through spearphishing attachments or links.
Mitigation strategies for CVE-2017-20116 should prioritize immediate patching of the affected TrueConf Server version to the latest available release that addresses this specific vulnerability. Organizations should implement comprehensive input validation and output encoding mechanisms to prevent similar issues in other applications, ensuring that all user-supplied data is properly sanitized before being incorporated into web responses. Network segmentation and access controls should be strengthened around administrative interfaces to limit potential attack surfaces, while regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other system components. Additionally, implementing web application firewalls and content security policies can provide additional layers of protection against reflected XSS attacks, and user education programs should be established to reduce the risk of social engineering attacks that leverage this vulnerability. The vulnerability demonstrates the critical importance of maintaining up-to-date software versions and implementing robust security controls in administrative interfaces that are exposed to potentially untrusted users.