CVE-2003-0702 in RealSecure Server Sensor
Summary
by MITRE
Unknown vulnerability in an ISAPI plugin for ISS Server Sensor 7.0 XPU 20.16, 20.18, and possibly other versions before 20.19, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code in Internet Information Server (IIS) via a certain URL through SSL.
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Analysis
by VulDB Data Team • 03/08/2021
The vulnerability identified as CVE-2003-0702 represents a critical security flaw within the ISAPI plugin component of ISS Server Sensor 7.0 XPU 20.16 and 20.18 versions, with potential impacts extending to other affected releases prior to XPU 20.19. This issue manifests through a specific URL access pattern that leverages SSL connections to exploit the underlying software component, creating a pathway for remote attackers to compromise system integrity and availability. The vulnerability resides in the ISAPI filter implementation that processes incoming requests through the Internet Information Services framework, specifically targeting the sensor plugin that monitors and analyzes web traffic for security events. The flaw demonstrates characteristics consistent with buffer overflow conditions or improper input validation within the plugin's request handling mechanism, which can be triggered by malformed or specially crafted URL parameters that bypass normal parsing procedures.
The technical exploitation of this vulnerability occurs through remote network access via SSL-encrypted connections, which adds an additional layer of complexity to the attack vector while maintaining the core threat of unauthorized system compromise. Attackers can construct malicious URL requests that, when processed by the vulnerable ISAPI plugin, cause the IIS server to crash or potentially execute arbitrary code within the context of the web server process. This represents a significant risk to organizations relying on ISS Server Sensor for security monitoring, as the attack can be executed without requiring local system access or authentication credentials. The vulnerability's classification aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-129, which covers improper validation of array indices, suggesting that the plugin fails to properly validate input parameters before processing them within memory buffers or array structures.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as the potential for arbitrary code execution creates opportunities for attackers to gain unauthorized access to sensitive server resources, escalate privileges, and establish persistent access points within the network infrastructure. Organizations utilizing affected versions of ISS Server Sensor face immediate risks to their web server availability and security posture, particularly when these systems are exposed to untrusted network traffic or when SSL connections are used for legitimate administrative access. The vulnerability's presence in the ISAPI plugin architecture means that successful exploitation could potentially compromise the entire IIS server environment, affecting multiple web applications hosted on the same server instance. This scenario aligns with ATT&CK technique T1210, which covers exploitation of remote services, and T1059, which describes execution through command and scripting interpreter.
Mitigation strategies for CVE-2003-0702 require immediate implementation of the vendor-provided patch for ISS Server Sensor 7.0 XPU 20.19 and subsequent releases, which address the underlying input validation issues within the ISAPI plugin component. Organizations should also consider implementing network-level restrictions that limit access to the vulnerable sensor plugin endpoints, particularly when SSL connections are involved, and establish monitoring procedures to detect anomalous URL access patterns that might indicate exploitation attempts. Security teams should conduct thorough vulnerability assessments to identify all systems running affected software versions and implement layered defense mechanisms including network segmentation, intrusion detection system rules, and application firewalls to prevent unauthorized access to vulnerable components. The vulnerability demonstrates the importance of maintaining up-to-date security software components and implementing proper security testing procedures for web server plugins and filters that interact with user-supplied input data.