CVE-2017-16766 in DiskStation Manager
Summary
by MITRE
An improper access control vulnerability in synodsmnotify in Synology DiskStation Manager (DSM) before 6.1.4-15217 and before 6.0.3-8754-6 allows local users to inject arbitrary web script or HTML via the -fn option.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 01/15/2025
The vulnerability CVE-2017-16766 represents a critical improper access control flaw within the synodsmnotify component of Synology DiskStation Manager DSM software. This issue affects versions prior to 6.1.4-15217 and 6.0.3-8754-6, creating a significant security risk for local users who can exploit this weakness to inject malicious web scripts or HTML content. The vulnerability specifically manifests through the -fn option parameter, which lacks proper input validation and sanitization mechanisms. This allows attackers with local system access to manipulate the notification service and potentially execute arbitrary code or deliver malicious payloads to unsuspecting users. The flaw resides in the application's failure to properly validate user-supplied input before processing it within the notification framework.
The technical exploitation of this vulnerability demonstrates a classic case of command injection or script injection, classified under CWE-79 which represents Cross-Site Scripting (XSS) vulnerabilities. The attack vector leverages the -fn option to pass malicious input directly into the notification system, bypassing normal access controls that should prevent local users from injecting arbitrary content. This weakness enables attackers to craft specially formatted input that gets processed by the synodsmnotify service, potentially leading to unauthorized code execution or data exfiltration. The vulnerability operates at the application level within the DSM operating system, making it particularly dangerous as it can be exploited by users who already have local access to the system, potentially escalating privileges or compromising other system components.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable more sophisticated attack chains within the Synology DSM environment. Local users who exploit this weakness can potentially deliver malicious payloads that persist across system sessions or compromise the integrity of the notification system itself. The vulnerability creates a persistent threat vector that could be leveraged by attackers who have already gained local access to the system, potentially allowing them to establish backdoors or perform further reconnaissance. This type of vulnerability aligns with ATT&CK technique T1059 which covers Command and Scripting Interpreter, specifically targeting the execution of malicious scripts through legitimate system interfaces. The impact is particularly concerning in enterprise environments where Synology DSM appliances serve as central storage and file sharing platforms, as compromise of these systems can lead to widespread data exposure and system infiltration.
Organizations should immediately implement the vendor-provided security patches for DSM versions 6.1.4-15217 and 6.0.3-8754-6 to remediate this vulnerability. System administrators should also consider implementing additional monitoring for unusual notification service activity and input validation mechanisms within the DSM environment. The vulnerability highlights the importance of proper input sanitization and access control validation within system services, particularly those handling user-provided data. Security teams should review their local privilege management policies and consider implementing principle of least privilege controls to minimize potential impact from similar vulnerabilities. This issue underscores the necessity of regular security assessments and patch management procedures, as well as the importance of validating all user inputs through robust sanitization and validation frameworks to prevent injection attacks at all levels of the application stack.