CVE-2020-9031 in SyncServer S100
Summary
by MITRE
Symmetricom SyncServer S100 2.90.70.3, S200 1.30, S250 1.25, S300 2.65.0, and S350 2.80.1 devices allow Directory Traversal via the FileName parameter to daemonlog.php.
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Analysis
by VulDB Data Team • 04/01/2024
The Symmetricom SyncServer series of time synchronization devices presents a critical directory traversal vulnerability that affects multiple model variants including S100, S200, S250, S300, and S350. This vulnerability resides in the daemonlog.php web interface component and specifically targets the FileName parameter which processes user-supplied input without adequate validation or sanitization. The flaw allows remote attackers to access arbitrary files on the device filesystem by manipulating the FileName parameter to traverse directory structures beyond the intended scope. This directory traversal vulnerability represents a significant security weakness that could enable unauthorized access to sensitive system information, configuration files, and potentially system credentials or logs that should remain protected within the device's internal file structure.
The technical implementation of this vulnerability stems from improper input validation within the daemonlog.php script which directly incorporates user-provided FileName parameter values into file access operations without proper path normalization or restriction checks. Attackers can exploit this by crafting malicious requests containing directory traversal sequences such as ../ or ..\ that allow them to navigate outside the intended directory boundaries and access files that should be restricted to authorized personnel only. This type of vulnerability maps directly to CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, which is classified as a path traversal or directory traversal attack pattern. The vulnerability exists in the web application layer of these industrial time synchronization devices, making it particularly dangerous as it can be exploited remotely without requiring physical access to the device.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attack vectors including system compromise and denial of service conditions. An attacker who successfully exploits this vulnerability could gain access to system logs, configuration files, and potentially sensitive operational data that would normally be protected within the device's secure file system. This could provide attackers with valuable information about the network topology, device configuration, and operational parameters that could be leveraged for further attacks against the broader network infrastructure. The vulnerability affects devices that are typically deployed in critical infrastructure environments where time synchronization is essential for network operations, making the potential impact of exploitation particularly severe in industrial control systems and network time protocol environments. According to ATT&CK framework, this vulnerability aligns with T1083 - File and Directory Discovery and T1566 - Phishing for Information, as it enables unauthorized file access and information gathering that could facilitate more advanced attacks.
Organizations should implement immediate mitigations including applying vendor patches when available, implementing network segmentation to limit access to these devices, and configuring proper firewall rules to restrict access to the affected web interface. Additionally, network monitoring should be enhanced to detect suspicious file access patterns that might indicate exploitation attempts. The vulnerability represents a clear violation of the principle of least privilege as it allows unrestricted file access to components that should only be accessible to authorized administrators. Security teams should also consider implementing intrusion detection systems that can identify and alert on directory traversal attempts, and conduct regular security assessments to identify similar vulnerabilities in other industrial control system components that may be susceptible to similar exploitation patterns.