CVE-1999-0060 in Ascend Router
Summary
by MITRE
Attackers can cause a denial of service in Ascend MAX and Pipeline routers with a malformed packet to the discard port, which is used by the Java Configurator tool.
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Analysis
by VulDB Data Team • 04/17/2026
The vulnerability described in CVE-1999-0060 represents a classic denial of service weakness affecting Ascend Max and Pipeline routers that was identified in the late 1990s. This issue specifically targets the discard port functionality within these network devices, which serves as a critical component for handling packets that do not match any defined routing rules. The vulnerability stems from insufficient input validation mechanisms within the router's packet processing logic, allowing malicious actors to craft specially malformed packets that exploit buffer handling deficiencies in the discard port implementation.
The technical flaw manifests when the router receives packets that exceed expected parameter limits or contain invalid structures within the discard port service. These malformed packets trigger unexpected behavior in the router's processing stack, leading to system instability and complete service interruption. The vulnerability is particularly concerning because it affects network infrastructure devices that form the backbone of communication networks, where availability is paramount for business operations and network reliability. The Java configurator tool mentioned in the description serves as the primary interface for managing router configurations, making the vulnerability exploitable through legitimate administrative channels that could be compromised.
The operational impact of this vulnerability extends beyond simple service disruption to encompass broader network reliability concerns and potential cascading failures within interconnected network topologies. When affected routers experience denial of service conditions, they cease to properly forward traffic, potentially isolating network segments and creating single points of failure that can propagate throughout larger network infrastructures. Network administrators face significant challenges in detecting and mitigating such attacks since they often appear as legitimate traffic anomalies rather than clear malicious activity patterns. The vulnerability also demonstrates poor defensive programming practices that violate fundamental security principles outlined in common weakness enumeration standards.
Security professionals should note that this vulnerability aligns with several ATT&CK framework techniques including T1498 for network denial of service and T1595 for network infiltration through service exploitation. The issue exemplifies the importance of input validation and proper error handling in network device firmware development, particularly when dealing with services that must process untrusted network traffic. Organizations should implement immediate mitigations including disabling unused services, applying firmware updates from Ascend, and configuring network access controls to restrict access to the discard port functionality. The vulnerability serves as a historical example of how inadequate security testing and validation of network infrastructure components can create persistent weaknesses that remain exploitable for years after initial deployment, highlighting the critical need for comprehensive security assessments throughout the network lifecycle.