CVE-2002-0778 in Cache Engine 505
Summary
by MITRE
The default configuration of the proxy for Cisco Cache Engine and Content Engine allows remote attackers to use HTTPS to make TCP connections to allowed IP addresses while hiding the actual source IP.
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Analysis
by VulDB Data Team • 06/17/2019
The vulnerability described in CVE-2002-0778 represents a significant security flaw in Cisco's caching and content delivery infrastructure products. This issue affects the default configuration of Cisco Cache Engine and Content Engine proxy systems, creating a dangerous misconfiguration that undermines network security controls. The flaw enables remote attackers to exploit the proxy's HTTPS handling capabilities to establish TCP connections to IP addresses that are typically restricted or allowed only through specific network pathways, while simultaneously masking their true source IP address through the proxy's transparent forwarding mechanism.
The technical implementation of this vulnerability stems from the proxy's default configuration that fails to properly enforce source IP address validation when processing HTTPS requests. When legitimate users access content through the proxy, the system processes these requests through standard HTTPS protocols while maintaining the original source IP information in its internal routing tables. However, the misconfiguration allows attackers to leverage this legitimate proxy functionality to make TCP connections to allowed IP addresses without revealing their actual source IP addresses, effectively creating a means of network reconnaissance and potential unauthorized access. This behavior violates fundamental network security principles by enabling attackers to bypass source address validation mechanisms that are typically enforced by firewalls and access control systems.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates opportunities for attackers to perform network reconnaissance, conduct port scanning, and potentially gain unauthorized access to systems that should be restricted to specific IP addresses or networks. Attackers can exploit this vulnerability to map network topologies, identify open ports on allowed IP addresses, and potentially escalate their privileges by leveraging the proxy's ability to forward connections to internal systems that would normally be protected by network segmentation controls. The hidden source IP addresses make it difficult for network administrators to trace attack origins or implement effective rate limiting and access control policies, significantly complicating incident response and forensic analysis efforts.
This vulnerability aligns with CWE-652 Improper Isolation or Compartmentalization, as it demonstrates a failure to properly isolate network traffic based on source identity, and relates to ATT&CK technique T1046 Network Service Scanning, where adversaries use proxy infrastructure to conduct network reconnaissance without revealing their true network position. The flaw also represents a violation of the principle of least privilege, as the proxy's default configuration allows for unauthorized access patterns that should be restricted to authorized network segments or users. Organizations using Cisco Cache Engine and Content Engine products must implement proper network segmentation, disable unnecessary proxy functionality, and configure explicit access controls that prevent the transparent forwarding of TCP connections while maintaining legitimate caching and content delivery services. The vulnerability underscores the critical importance of proper security configuration management and the need for regular security assessments of network infrastructure components to prevent such misconfigurations from creating exploitable attack vectors in enterprise networks.