CVE-2000-0569 in Sygate
Summary
by MITRE
Sybergen Sygate allows remote attackers to cause a denial of service by sending a malformed DNS UDP packet to its internal interface.
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Analysis
by VulDB Data Team • 03/14/2025
The vulnerability identified as CVE-2000-0569 represents a critical denial of service weakness within Sybergen Sygate security products, specifically affecting the handling of DNS UDP packets on internal network interfaces. This flaw exploits a fundamental parsing error in the network traffic processing mechanism, where the system fails to properly validate incoming DNS UDP packets before attempting to process them. The vulnerability stems from inadequate input validation and error handling procedures that allow malformed packets to disrupt normal system operations.
The technical implementation of this vulnerability occurs when a remote attacker crafts and transmits specially formatted DNS UDP packets to the internal interface of Sygate systems. These malformed packets contain structures that the system's DNS processing module cannot properly interpret or handle, leading to system instability and eventual service interruption. The flaw operates at the network protocol level, specifically targeting the User Datagram Protocol implementation within the DNS handling component. According to CWE standards, this vulnerability maps to CWE-129, which describes improper validation of input boundaries, and CWE-400, which addresses unspecified denial of service conditions. The attack vector requires only network access to the internal interface, making it particularly dangerous as it can be exploited from within the network perimeter.
The operational impact of this vulnerability extends beyond simple service disruption, as it can compromise the overall security posture of networks relying on Sygate for protection. When exploited, the denial of service condition can render the security appliance ineffective, leaving network segments vulnerable to other attacks while the system remains unavailable. Organizations may experience extended downtime during incident response and system restoration, potentially affecting business continuity and security operations. The vulnerability affects the availability aspect of the CIA triad, specifically targeting the system's ability to maintain continuous operation. From an ATT&CK framework perspective, this vulnerability aligns with T1499.004, which covers network denial of service, and represents a critical weakness that could enable subsequent exploitation attempts.
Mitigation strategies for this vulnerability should include immediate patch deployment from Sybergen, network segmentation to isolate affected systems, and implementation of network monitoring to detect malformed packet patterns. Organizations should also consider implementing rate limiting and packet filtering rules to prevent exploitation attempts. The fundamental fix requires proper input validation and error handling within the DNS UDP packet processing code, ensuring that malformed packets are either rejected or properly sanitized before processing. Network administrators should conduct thorough vulnerability assessments to identify all instances of Sygate products within their environment and ensure consistent patch management protocols are maintained. Additionally, implementing intrusion detection systems with signature-based detection for this specific vulnerability can provide early warning capabilities and help prevent successful exploitation attempts.