CVE-2026-40533 in DiskStation Manager
Summary
by MITRE • 09/18/2026
An exposure of sensitive information through data queries vulnerability in Desktop API in Synology DiskStation Manager (DSM) before 7.2.1-69057-10, 7.2.2-72806-7 and 7.3.2-86009-2 allows remote attackers to obtain non-sensitive information.
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified in Synology DiskStation Manager (DSM) represents a critical failure in access control mechanisms within the Desktop API, specifically affecting versions prior to 7.2.1-69057-10, 7.2.2-72806-7, and 7.3.2-86009-2. This flaw allows remote attackers to exploit improper authorization checks when interacting with the API endpoints responsible for managing desktop environments on Synology NAS devices. The core technical issue stems from a lack of sufficient verification regarding user permissions or session validity during data query operations, enabling unauthorized entities to retrieve information that should be restricted based on their privilege level. Although the vulnerability is categorized as an exposure of sensitive information through data queries, it is important to note that the specific data disclosed in this instance is described as non-sensitive. This distinction implies that while the mechanism for information leakage exists and could theoretically be leveraged for more critical data if other vulnerabilities are present or if the scope of accessible endpoints varies by configuration, the immediate impact involves the disclosure of metadata or system details rather than direct access to private user files or credentials.
From a technical perspective, this vulnerability aligns with CWE-200, which defines an exposure of sensitive information where the data is not necessarily critical but can aid in further attacks such as reconnaissance or social engineering. The attack vector is remote and requires no authentication for certain endpoints, classifying it under ATT&CK technique T1595, specifically Active Scanning, as attackers can enumerate system capabilities and version details to tailor subsequent exploits. By querying the Desktop API without proper authorization checks, an attacker can gather information about the DSM version, installed packages, network configuration hints, or other operational parameters that are typically hidden from unauthenticated users. This level of disclosure reduces the effort required for an adversary to identify known vulnerabilities associated with specific DSM versions and their corresponding patches, thereby facilitating targeted attack campaigns against organizations running these outdated firmware releases.
The operational impact of this vulnerability is primarily centered on information gathering and reconnaissance rather than immediate data exfiltration or system compromise. However, in security architecture, even non-sensitive information can be weaponized when combined with other weaknesses. For instance, knowing the exact DSM version allows attackers to search for public exploit databases like Exploit-DB or CVE details that might reveal additional flaws specific to that build number. Furthermore, if this API endpoint is exposed directly to the internet without proper network segmentation or a Web Application Firewall (WAF) configured with strict rate limiting and access controls, it serves as an open door for automated scanning tools used by botnets to identify vulnerable Synology devices globally. The presence of such information leakage indicates a broader pattern of insufficient input validation and authorization enforcement within the DSM web interface components, suggesting that other API endpoints may suffer from similar or more severe flaws.
Mitigation strategies must prioritize immediate patching as the primary defense mechanism. Administrators running affected versions should upgrade to Synology DiskStation Manager version 7.2.1-69057-10, 7.2.2-72806-7, or later stable releases where these authorization checks have been corrected by Synology’s development team. In environments where immediate patching is not feasible due to operational constraints, network-level controls should be implemented to restrict access to the DSM web interface and API endpoints exclusively from trusted internal IP ranges using firewalls or VPNs. Additionally, deploying a reverse proxy with strict authentication requirements can prevent unauthenticated requests from reaching the vulnerable backend services. Regular security audits of exposed ports and continuous monitoring for anomalous query patterns against the Desktop API are also recommended to detect potential exploitation attempts in real-time. Organizations should treat this vulnerability as an indicator that their perimeter defenses may be insufficiently hardened, necessitating a review of overall exposure management practices for network-attached storage devices.