CVE-2002-0209 in Alteon ACEdirector
Summary
by MITRE
Nortel Alteon ACEdirector WebOS 9.0, with the Server Load Balancing (SLB) and Cookie-Based Persistence features enabled, allows remote attackers to determine the real IP address of a web server with a half-closed session, which causes ACEdirector to send packets from the server without changing the address to the virtual IP address.
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Analysis
by VulDB Data Team • 09/24/2024
The vulnerability identified as CVE-2002-0209 represents a significant security flaw in Nortel Alteon ACEdirector WebOS version 9.0 that affects load balancing and persistence mechanisms. This issue specifically impacts systems utilizing Server Load Balancing (SLB) and Cookie-Based Persistence features, creating a critical disclosure risk that can be exploited by remote attackers to uncover the actual server IP addresses within the network infrastructure. The flaw operates through a fundamental misconfiguration in how the system handles network sessions and address translation processes.
The technical implementation of this vulnerability stems from the ACEdirector's improper handling of half-closed TCP sessions within its load balancing architecture. When the SLB and Cookie-Based Persistence features are enabled, the system fails to maintain proper address translation boundaries during session termination phases. This misconfiguration allows attackers to establish connections that remain in a half-closed state, where the system continues to forward packets using the original server IP address rather than the configured virtual IP address. The underlying mechanism involves the system's inability to properly enforce network address translation rules during these transitional session states, creating a direct pathway for IP address exposure.
The operational impact of this vulnerability extends beyond simple information disclosure, as it fundamentally compromises the network's security architecture by breaking the intended isolation between external clients and internal server infrastructure. Attackers can leverage this weakness to map internal network topology, identify specific server locations, and potentially escalate their attacks to target vulnerable backend systems directly. This vulnerability directly violates security principles of network segmentation and address obfuscation that are fundamental to protecting internal infrastructure from external reconnaissance and exploitation attempts.
The flaw aligns with CWE-200, which addresses "Information Exposure," and demonstrates how improper session management can lead to unintended information disclosure. From an attacker's perspective, this vulnerability maps to ATT&CK technique T1082, "System Information Discovery," as it enables reconnaissance activities that reveal internal IP addressing schemes. The vulnerability also relates to T1566, "Phishing with Spoofed Delivery" and T1590, "Reconnaissance," as attackers can use the exposed IP information to craft more targeted attacks against specific internal systems.
Mitigation strategies for this vulnerability require immediate implementation of configuration changes that disable or properly configure the affected features within the ACEdirector system. Organizations should disable the Server Load Balancing and Cookie-Based Persistence features if they are not essential for operations, or ensure that proper session management policies are implemented to prevent half-closed session handling. Network administrators must also implement proper firewall rules and access controls to limit the exposure of internal IP addresses, while monitoring for unusual connection patterns that might indicate exploitation attempts. Additionally, regular security assessments should verify that address translation mechanisms function correctly and that session termination processes maintain proper network boundary enforcement. The vulnerability underscores the critical importance of maintaining proper session state management in load balancing systems and demonstrates how seemingly minor configuration flaws can create significant security risks in network infrastructure.