CVE-2026-71932 in VigorSwitch
Summary
by MITRE • 08/24/2026
Multiple DrayTek VigorSwitch models contain a directory traversal vulnerability in the getSyslogFile function. The vulnerability is caused by insufficient validation of the option field. A remote attacker can trigger this vulnerability via crafted input containing path traversal sequences to access arbitrary files on the device. Exploitation requires valid administrative credentials for the device's web management interface.
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Analysis
by VulDB Data Team • 08/24/2026
The identified security flaw resides within the getSyslogFile function of multiple DrayTek VigorSwitch models, representing a classic directory traversal vulnerability stemming from insufficient input validation. This specific implementation error occurs because the software fails to adequately sanitize or verify the option field provided by the user before using it in file system operations. When an attacker supplies crafted input containing path traversal sequences, such as dot-dot-slash characters, the application interprets these strings literally rather than rejecting them as invalid paths. Consequently, this allows the manipulation of intended directory structures, enabling access to files and directories that reside outside the restricted scope originally defined by the developer. This type of vulnerability is formally categorized under CWE-22: Improper Limitation of a Pathname to a Restricted Directory within standard security taxonomy frameworks.
The operational impact of exploiting this flaw is significant for organizations relying on these network switches for infrastructure connectivity and monitoring. By leveraging this directory traversal, an authenticated attacker can read arbitrary files from the device's file system. This capability potentially exposes sensitive configuration data, internal logs containing network topology details, or even credential hashes stored in plaintext if present. The exposure of such information facilitates further reconnaissance activities, allowing adversaries to map out the internal network structure and identify other potential targets for lateral movement. Furthermore, depending on the specific files accessible, an attacker might gain insights into system architecture that could aid in crafting more sophisticated attacks against connected devices or services running on the switch itself.
It is critical to note that exploitation of this vulnerability requires valid administrative credentials for the device's web management interface. This authentication requirement places the risk profile within the context of authenticated remote code execution or information disclosure scenarios, aligning with ATT&CK techniques related to Collection and Exfiltration over internal networks. While the barrier of needing admin access reduces the immediate threat from unauthenticated internet scanners, it does not eliminate the danger posed by insider threats, compromised administrative accounts, or social engineering attacks that could yield these credentials. Once an attacker obtains valid login details, they can interact with the vulnerable function to extract sensitive system files without triggering typical intrusion detection alerts associated with brute-force attempts or unauthorized access patterns.
To mitigate this vulnerability, immediate action should be taken by updating the firmware on all affected DrayTek VigorSwitch models to a version that includes patches for this directory traversal issue. Administrators must ensure they are running the latest stable release provided by the vendor, as older versions retain the flawed input validation logic in the getSyslogFile function. In addition to software updates, organizations should enforce strict access controls on the web management interface, ensuring that administrative privileges are granted only to essential personnel and protected by strong, unique passwords or multi-factor authentication where supported. Regular auditing of user accounts and monitoring for unusual login patterns can also help detect potential compromise attempts before they lead to successful exploitation of this flaw.