CVE-2018-7658 in Network Time System
Summary
by MITRE
NTSServerSvc.exe in the server in Softros Network Time System 2.3.4 allows remote attackers to cause a denial of service (daemon crash) by sending exactly 11 bytes.
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Analysis
by VulDB Data Team • 09/16/2025
The vulnerability identified as CVE-2018-7658 affects the NTSServerSvc.exe component within Softros Network Time System version 2.3.4, representing a critical denial of service weakness that can be exploited remotely. This flaw exists within the server daemon responsible for network time synchronization services, making it a significant concern for organizations relying on accurate timekeeping infrastructure. The vulnerability manifests when the service receives a specifically crafted 11-byte payload, causing the daemon to crash and terminate its operations. This type of vulnerability falls under the category of improper input validation, where the system fails to properly handle or sanitize incoming data streams before processing them. The attack vector is particularly concerning as it requires no authentication or privileged access, allowing any remote attacker to potentially disrupt time synchronization services across networked environments. The impact extends beyond simple service interruption since network time synchronization is fundamental to security operations, log correlation, and system integrity across enterprise infrastructures. Organizations using this software may experience cascading failures as dependent systems lose their ability to maintain synchronized time stamps, potentially compromising security event logging and forensic analysis capabilities.
The technical implementation of this vulnerability demonstrates a classic buffer overflow or input parsing flaw where the NTSServerSvc.exe process does not adequately validate the length or content of incoming data packets. When exactly 11 bytes are transmitted to the service, the program fails to handle this specific data size appropriately, resulting in an abrupt termination of the daemon process. This behavior aligns with CWE-129, which addresses improper validation of length of input data, and CWE-787, concerning out-of-bounds write operations. The vulnerability operates at the protocol level where the service expects a certain data format and size but receives malformed input that causes memory corruption or unexpected program termination. From an operational perspective, this represents a low-effort, high-impact attack vector that could be easily automated, making it particularly dangerous in environments where network time synchronization is critical for security operations. The daemon crash creates a window of opportunity for attackers to disrupt time-sensitive operations, potentially affecting authentication systems, security monitoring tools, and compliance reporting mechanisms that depend on accurate time stamps.
The operational impact of CVE-2018-7658 extends far beyond the immediate service disruption, as network time synchronization is foundational to numerous security and operational functions within enterprise environments. When the NTSServerSvc.exe daemon crashes, it can lead to cascading failures throughout the network infrastructure, as various systems lose their ability to maintain synchronized time references. This disruption affects security information and event management systems, intrusion detection systems, and audit logging mechanisms that rely on consistent time stamps for proper correlation and analysis. The vulnerability's remote exploitability means that attackers can target this weakness from anywhere on the network without requiring local access or credentials, making it particularly attractive for adversaries seeking to disrupt operations. From an attack technique perspective, this vulnerability aligns with ATT&CK tactic TA0043 (Reconnaissance) and TA0040 (Defense Evasion) as it enables initial reconnaissance of target systems and can be used to evade detection by creating noise in system logs or causing service disruptions that mask other malicious activities. The impact is particularly severe in regulated environments where time synchronization is mandated for compliance purposes, as service disruptions could result in regulatory violations and potential penalties.
Organizations should implement immediate mitigations to address this vulnerability, including applying the vendor-provided patch or update that resolves the input validation issue in NTSServerSvc.exe. Network segmentation and firewall rules should be implemented to restrict access to the time synchronization service, limiting exposure to unauthorized remote connections. Monitoring should be enhanced to detect unusual patterns in time synchronization service availability and to alert on potential exploitation attempts. System administrators should also consider implementing intrusion detection systems that can identify the specific 11-byte payload pattern associated with this vulnerability. The remediation process should include comprehensive testing to ensure that the patch does not introduce compatibility issues with existing network time synchronization protocols. Organizations should also review their overall time synchronization strategy to reduce dependency on a single service and implement redundant time sources to minimize the impact of any single point of failure. Additionally, regular vulnerability assessments should be conducted to identify similar input validation weaknesses in other network services that may be susceptible to similar exploitation techniques. The incident response plan should include specific procedures for handling time synchronization service disruptions, ensuring that operations can continue with minimal impact while the vulnerability is being addressed.