CVE-2018-0473 in IOS
Summary
by MITRE
A vulnerability in the Precision Time Protocol (PTP) subsystem of Cisco IOS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition of the Precision Time Protocol. The vulnerability is due to insufficient processing of PTP packets. An attacker could exploit this vulnerability by sending a custom PTP packet to, or through, an affected device. A successful exploit could allow the attacker to cause a DoS condition for the PTP subsystem, resulting in time synchronization issues across the network.
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Analysis
by VulDB Data Team • 05/22/2023
The vulnerability identified as CVE-2018-0473 resides within the Precision Time Protocol subsystem of Cisco IOS Software, representing a critical security flaw that undermines network time synchronization capabilities. This issue specifically affects devices that implement PTP for precise time coordination across network infrastructure, making it particularly concerning for environments requiring accurate timing such as financial trading systems, telecommunications networks, and industrial control systems. The vulnerability stems from inadequate validation and processing mechanisms within the PTP packet handling logic, creating an exploitable condition that can be leveraged by remote attackers without requiring authentication credentials.
The technical flaw manifests through insufficient input validation of PTP packets, where the affected Cisco IOS Software fails to properly sanitize or process malformed or specially crafted PTP messages. This weakness allows an attacker to construct and transmit custom PTP packets that, when received by an affected device, trigger unexpected behavior within the PTP subsystem. The vulnerability operates at the network protocol level, specifically targeting the PTP implementation within the IOS operating system, and can be exploited through various network paths including direct connections or through network devices that forward PTP traffic. According to CWE classification, this represents a weakness in input validation and processing of network protocol data, falling under CWE-20 for improper input validation.
The operational impact of CVE-2018-0473 extends beyond simple service disruption, as it creates cascading effects throughout network infrastructure that depends on accurate time synchronization. When exploited successfully, the vulnerability can cause complete denial of service for the PTP subsystem, leading to widespread time synchronization failures across connected devices and potentially disrupting critical network operations. Network administrators may observe intermittent or complete loss of time synchronization, which can affect services such as network monitoring, logging systems, security event correlation, and time-sensitive applications that rely on precise temporal coordination. The disruption can propagate through network segments as devices lose their ability to maintain synchronized time references, potentially causing further operational complications in time-critical environments.
Mitigation strategies for this vulnerability should prioritize immediate patch application from Cisco, as the company released security advisories and software updates specifically addressing this issue. Network administrators must conduct thorough vulnerability assessments to identify all affected devices within their infrastructure and implement network segmentation to limit potential attack vectors. Additional protective measures include implementing network access controls to restrict PTP packet transmission, deploying intrusion detection systems capable of monitoring for suspicious PTP traffic patterns, and establishing monitoring procedures to detect anomalous time synchronization behavior. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving denial of service and protocol manipulation, while also potentially enabling lateral movement if attackers can leverage the time synchronization disruption to interfere with security systems that depend on accurate timestamps. Organizations should also consider implementing redundant time synchronization mechanisms and maintaining detailed network time synchronization logs to facilitate incident response and forensic analysis in case of exploitation.