CVE-2002-0818 in wwwoffle
Summary
by MITRE
wwwoffled in World Wide Web Offline Explorer (WWWOFFLE) allows remote attackers to cause a denial of service and possibly execute arbitrary code via a negative Content-Length value.
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Analysis
by VulDB Data Team • 09/13/2025
The CVE-2002-0818 vulnerability affects wwwoffled, a component of World Wide Web Offline Explorer, which is a web caching and offline browsing tool designed to allow users to download web content for offline access. This vulnerability represents a critical security flaw that exists in how the software processes HTTP response headers, specifically the Content-Length field that indicates the size of the response body. The vulnerability stems from insufficient input validation and sanitization mechanisms within the wwwoffled component, which fails to properly handle malformed HTTP headers that could be exploited by remote attackers to compromise the system's integrity and availability.
The technical flaw manifests when wwwoffled encounters a negative Content-Length value in HTTP responses from web servers. This particular vulnerability falls under the category of improper input validation as classified by CWE-20, where the software does not adequately validate or sanitize input data received from external sources. The negative Content-Length value creates a scenario where the application's internal buffer management and memory allocation routines become compromised, leading to potential memory corruption and arbitrary code execution. When the application attempts to process this malformed header, it can cause unpredictable behavior in the memory management subsystem, potentially resulting in stack overflows, heap corruption, or other memory-related vulnerabilities that can be exploited by malicious actors.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable remote code execution on systems running vulnerable versions of wwwoffled. Attackers can leverage this flaw to cause the application to crash or become unresponsive, effectively creating a denial of service condition that disrupts legitimate user access to offline browsing capabilities. More critically, the vulnerability can be exploited to execute arbitrary code with the privileges of the wwwoffled process, which typically runs with elevated permissions on the system. This represents a significant risk to system integrity and confidentiality, as successful exploitation could allow attackers to gain unauthorized access to sensitive data, install malicious software, or establish persistent access to the compromised system. The vulnerability is particularly concerning in environments where offline browsing is used for sensitive corporate or personal data access, as it could provide a pathway for unauthorized data exfiltration or system compromise.
Mitigation strategies for CVE-2002-0818 should focus on immediate patching of vulnerable versions of World Wide Web Offline Explorer, as this represents the most effective defense against exploitation. Organizations should implement network segmentation and access controls to limit exposure of systems running wwwoffled to untrusted networks and users. Additionally, network monitoring solutions should be configured to detect and alert on anomalous Content-Length header values that could indicate attempted exploitation of this vulnerability. The implementation of web application firewalls and intrusion detection systems can help identify and block malicious HTTP requests containing negative Content-Length values. System administrators should also consider implementing least privilege principles for the wwwoffled service, running it with minimal necessary permissions to limit potential damage from successful exploitation. Regular security assessments and vulnerability scanning should be conducted to identify other potential vulnerabilities in the offline browsing infrastructure and ensure that all components are updated to their latest secure versions. This vulnerability demonstrates the importance of proper input validation and sanitization in network applications, aligning with ATT&CK technique T1210 for exploitation of remote services and T1499 for network denial of service attacks.