CVE-2017-20117 in Server
Summary
by MITRE • 06/29/2022
A vulnerability was found in TrueConf Server 4.3.7. It has been declared as problematic. Affected by this vulnerability is an unknown functionality of the file /admin/group. The manipulation leads to basic cross site scripting (DOM). The attack can 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-2017-20117 represents a critical cross site scripting flaw within TrueConf Server version 4.3.7, specifically affecting the administrative group management functionality. This issue resides in the /admin/group file component of the server software, where improper input validation allows malicious actors to inject malicious scripts into the application's DOM. The vulnerability classification aligns with CWE-79 which specifically addresses cross site scripting flaws in web applications. The attack vector is remote, meaning that an attacker can exploit this vulnerability without requiring physical access to the target system, making it particularly dangerous for enterprise environments where such servers are often exposed to external networks. The disclosure of the exploit to the public community significantly increases the risk profile, as it provides threat actors with readily available tools to target vulnerable installations.
The technical implementation of this DOM-based cross site scripting vulnerability occurs when user-supplied input is improperly handled within the administrative group management interface. When an attacker crafts malicious input and submits it through the affected endpoint, the server fails to properly sanitize or escape the data before rendering it within the browser context. This allows the injected script to execute in the victim's browser session, potentially enabling attackers to steal session cookies, perform unauthorized administrative actions, or redirect users to malicious websites. The DOM-based nature of this vulnerability means that the malicious script is executed directly within the client-side environment rather than being stored on the server, making traditional server-side defenses less effective against this specific attack pattern. This particular vulnerability demonstrates a failure in the application's input validation and output encoding mechanisms, which are fundamental security controls recommended by the OWASP Top Ten Project and aligned with NIST SP 800-163 security guidelines for web application development.
The operational impact of CVE-2017-20117 extends beyond simple script execution, as successful exploitation could enable attackers to gain unauthorized access to administrative functions within the TrueConf Server environment. This could result in complete compromise of the communication infrastructure, allowing threat actors to manipulate group configurations, access sensitive meeting data, or potentially escalate privileges to gain broader system control. The vulnerability's remote exploitability means that attackers can target multiple installations simultaneously, particularly if the server is accessible from the internet without proper network segmentation. Organizations utilizing this software may face significant operational disruption, data breaches, and potential compliance violations, especially in regulated environments where communication security is paramount. The public disclosure of the exploit increases the likelihood of automated attacks targeting vulnerable systems, as demonstrated by similar vulnerabilities in the ATT&CK framework that show how public exploits often lead to widespread compromise across organizations. Security teams must immediately assess their TrueConf Server installations for this vulnerability and implement appropriate mitigations to prevent unauthorized access to their communication infrastructure.
Organizations should prioritize immediate remediation of this vulnerability by upgrading to a patched version of TrueConf Server or implementing compensating controls such as web application firewalls that can detect and block malicious script injection attempts. The mitigation strategy should include input validation at multiple layers, including client-side and server-side validation, proper output encoding for all dynamic content, and regular security assessments of administrative interfaces. Network segmentation and access controls should be implemented to limit exposure of administrative endpoints to untrusted networks. Security monitoring should be enhanced to detect anomalous activity in the /admin/group endpoint, and incident response procedures should be updated to address potential exploitation of this vulnerability. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect against cross site scripting attacks that can compromise entire communication infrastructures.