CVE-2002-1535 in Raptor Firewall
Summary
by MITRE
Secure Webserver 1.1 in Raptor 6.5 and Symantec Enterprise Firewall 6.5.2 allows remote attackers to identify IP addresses of hosts on the internal network via a CONNECT request, which generates different error messages if the host is present.
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Analysis
by VulDB Data Team • 07/02/2024
This vulnerability exists in the Secure Webserver 1.1 component of Raptor 6.5 and Symantec Enterprise Firewall 6.5.2 software, representing a significant information disclosure flaw that enables remote attackers to perform network reconnaissance. The vulnerability stems from the server's inconsistent error handling behavior when processing CONNECT requests, which are typically used in http proxy operations to establish connections to remote hosts. When an attacker sends a CONNECT request to a host that exists within the internal network, the server responds with a different error message compared to when the host does not exist, creating a timing or response-based fingerprinting mechanism that reveals internal network topology.
The technical implementation of this vulnerability operates through the fundamental design flaw in how the Secure Webserver handles network connectivity verification during proxy operations. When a CONNECT request is received, the server performs a lookup of the target host, but instead of providing uniform error responses regardless of host existence, it generates distinct error messages that contain information about the network state. This differential response behavior constitutes a form of side-channel information leakage that can be exploited by attackers to map internal network structures without direct access to the internal network segments.
From an operational impact perspective, this vulnerability represents a critical security risk that enables attackers to perform network enumeration and mapping activities from outside the organization's network perimeter. The ability to identify internal host IP addresses through simple CONNECT requests allows threat actors to build detailed network maps that can be used for subsequent attacks, including targeted exploitation of specific systems, network segmentation analysis, and planning of more sophisticated attack vectors. This information disclosure can significantly reduce the attack surface and provide attackers with valuable intelligence for privilege escalation and lateral movement within the network.
The vulnerability aligns with CWE-209, Information Exposure Through an Error Message, which describes how error messages can reveal sensitive system information, and follows the ATT&CK technique T1046 for Network Service Scanning. Organizations should implement immediate mitigations including disabling unnecessary proxy functionality, implementing proper access controls to restrict CONNECT request handling, and deploying network monitoring solutions to detect and alert on suspicious CONNECT request patterns. Additionally, firewall rules should be configured to limit external access to proxy services and ensure that error messages do not contain detailed network information that could aid attackers in reconnaissance activities. The remediation process should also involve regular security assessments to identify similar information disclosure vulnerabilities in other network services and applications that may exhibit similar behavioral inconsistencies during error handling operations.