CVE-2026-13656 in DiskStation Manager
Summary
by MITRE • 11/12/2026
An improper neutralization of input during web page generation vulnerability in the Audio Player in Synology DiskStation Manager (DSM) before 7.3.2-86009-5 and 7.4.1-90080-1 allows remote authenticated users to read or write specific files.
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Analysis
by VulDB Data Team • 11/12/2026
The vulnerability identified involves an improper neutralization of input during web page generation within the Audio Player component of Synology DiskStation Manager (DSM). This flaw affects versions prior to 7.3.2-86009-5 and 7.4.1-90080-1, presenting a significant security risk for administrators who have authenticated access to the NAS device. The core issue stems from insufficient validation or sanitization of user-supplied input when it is processed by the web interface components responsible for rendering audio playback pages. When an attacker provides specially crafted input parameters, the system fails to properly escape or neutralize these values before incorporating them into dynamic content generation processes.
This technical flaw allows remote authenticated users to perform unauthorized file read and write operations on the underlying operating system of the NAS device. By exploiting this weakness in the web page generation logic, an attacker can manipulate file paths or parameters that are subsequently interpreted by the server-side scripts without adequate checks for directory traversal or path normalization. This capability effectively bypasses intended access controls, granting the authenticated user privileges to interact with files outside their designated scope. The ability to read sensitive configuration files could lead to further compromise of system integrity, while write capabilities may allow an attacker to inject malicious code into existing web pages or replace legitimate binaries, potentially establishing persistence on the device.
From a classification perspective, this vulnerability aligns closely with CWE-79, which describes Improper Neutralization of Input During Web Page Generation, commonly known as Cross-Site Scripting (XSS), although in this specific context, it extends beyond script injection to include server-side file system manipulation due to the nature of the input processing. It also relates to CWE-22, Improvement Control: Path Traversal, if the exploitation involves navigating directory structures to access restricted files. In terms of offensive security frameworks, such an attack vector is consistent with ATT&CK technique T1059, Command and Scripting Interpreter, particularly when used in conjunction with T1083, File and Directory Discovery, or T1222, File Permission Modification, depending on the specific outcome achieved by the attacker.
The operational impact of this vulnerability is severe for organizations relying on Synology NAS devices for critical data storage and management. Since authentication is required to exploit the flaw, it targets users who have already gained a foothold within the network perimeter or whose credentials have been compromised through other means such as phishing or credential stuffing attacks. Once authenticated access is established, this vulnerability serves as an escalation path that transforms standard user privileges into administrative-level file system control. This can lead to data exfiltration of sensitive business information stored on the NAS, corruption of critical system files leading to service disruption, or the installation of backdoors for long-term unauthorized access.
Mitigation strategies must prioritize immediate patching to address this flaw at its source. Administrators should upgrade their Synology DiskStation Manager software to version 7.3.2-86009-5 or later, and versions 7.4.1-90080-1 or later, where the input handling logic in the Audio Player has been corrected to properly neutralize malicious inputs. Until patches are applied, organizations should enforce strict network segmentation to limit access to DSM interfaces from untrusted networks. Additionally, implementing multi-factor authentication for all administrative accounts can reduce the likelihood of an attacker achieving the initial authenticated state required to exploit this vulnerability. Regular auditing of user permissions and monitoring for unusual file system activity on NAS devices can also help detect potential exploitation attempts early in their lifecycle.