CVE-2017-9554 in DiskStation Manager
Summary
by MITRE
An information exposure vulnerability in forget_passwd.cgi in Synology DiskStation Manager (DSM) before 6.1.3-15152 allows remote attackers to enumerate valid usernames via unspecified vectors.
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Analysis
by VulDB Data Team • 01/15/2025
The vulnerability identified as CVE-2017-9554 represents a critical information exposure flaw within Synology DiskStation Manager's password reset functionality. This issue affects the forget_passwd.cgi component in DSM versions prior to 6.1.3-15152, creating a significant security risk that enables remote attackers to systematically identify valid user accounts within the system. The vulnerability stems from insufficient input validation and response handling mechanisms that fail to properly obscure the distinction between valid and invalid usernames during the password recovery process.
The technical implementation of this flaw allows attackers to exploit unspecified vectors within the password reset mechanism to perform user enumeration attacks. When a user attempts to reset their password through the forget_passwd.cgi interface, the system's response behavior varies depending on whether the provided username exists in the system. This differential response creates a timing or error code pattern that attackers can leverage to determine which usernames are legitimate within the DiskStation Manager environment. The vulnerability aligns with CWE-200, which specifically addresses information exposure through improper error handling and response differentiation.
From an operational perspective, this vulnerability significantly undermines the security posture of affected Synology DiskStation installations by enabling credential stuffing and brute force attacks against valid accounts. Attackers can systematically test numerous username combinations to identify valid accounts, which then become targets for further exploitation including password spraying attacks or more sophisticated credential compromise techniques. The impact extends beyond simple account enumeration as it provides attackers with a foothold for subsequent attacks, potentially leading to full system compromise. This vulnerability directly maps to attack patterns described in the MITRE ATT&CK framework under T1078 for valid accounts and T1110 for credential access.
The security implications of this vulnerability are particularly severe given that DiskStation Manager serves as a central storage and file sharing platform for many organizations and individuals. The ability to enumerate valid usernames without authentication creates a reconnaissance opportunity that significantly reduces the time and effort required for successful attacks. Organizations running affected DSM versions face increased risk of unauthorized access to sensitive data stored on their network-attached storage systems. The vulnerability demonstrates poor security design principles in the password recovery module and highlights the importance of implementing consistent error responses and input validation to prevent information leakage. Effective mitigation strategies include updating to DSM version 6.1.3-15152 or later, implementing additional network-level controls, and monitoring for suspicious authentication attempts. Organizations should also consider implementing account lockout mechanisms and multi-factor authentication to reduce the impact of successful enumeration attacks.