CVE-2002-0990 in Enterprise Firewall
Summary
by MITRE
The web proxy component in Symantec Enterprise Firewall (SEF) 6.5.2 through 7.0, Raptor Firewall 6.5 and 6.5.3, VelociRaptor, and Symantec Gateway Security allow remote attackers to cause a denial of service (connection resource exhaustion) via multiple connection requests to domains whose DNS server is unresponsive or does not exist, which generates a long timeout.
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Analysis
by VulDB Data Team • 10/26/2024
The vulnerability identified as CVE-2002-0990 represents a critical denial of service weakness within Symantec's firewall and proxy security solutions. This flaw affects multiple products including Symantec Enterprise Firewall versions 6.5.2 through 7.0, Raptor Firewall versions 6.5 and 6.5.3, VelociRaptor, and Symantec Gateway Security. The vulnerability specifically resides in the web proxy component that handles incoming connection requests from remote attackers. The flaw manifests when attackers exploit the system's handling of DNS resolution failures by initiating multiple connection requests to domains with non-responsive or non-existent DNS servers. This exploitation pattern creates a cascading effect where the proxy component becomes overwhelmed with connection attempts that generate extended timeout periods, ultimately exhausting available connection resources.
The technical mechanism behind this vulnerability involves the proxy component's inadequate handling of failed DNS resolution attempts. When a connection request is made to a domain with an unresponsive DNS server, the proxy system enters a prolonged timeout state while attempting to resolve the domain name. This timeout process consumes valuable system resources including memory and connection slots, which are finite and limited. The vulnerability is classified under CWE-400 as an uncontrolled resource consumption issue, specifically involving denial of service through resource exhaustion. The flaw demonstrates poor error handling and resource management within the proxy component, where failed DNS lookups are not properly terminated or limited in their resource consumption. Attackers can amplify this vulnerability by creating multiple simultaneous connection attempts to domains with non-existent or unresponsive DNS servers, effectively creating a resource starvation condition.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire security infrastructure. When connection resources are exhausted, legitimate users and systems attempting to access network services may be denied access, creating a denial of service condition that affects the organization's operational continuity. The vulnerability affects the availability aspect of the security infrastructure, which is critical for maintaining network security posture. Organizations relying on these Symantec products for network protection may find their security controls rendered ineffective during an attack, as the proxy component becomes unable to process legitimate connection requests. This vulnerability also represents a significant risk to network availability and can be exploited by attackers to disrupt business operations. The attack vector is particularly concerning as it requires minimal technical expertise and can be executed remotely without authentication, making it accessible to a broad range of threat actors. The long timeout periods generated by failed DNS resolutions compound the impact, as system resources remain tied up for extended periods, reducing the overall system capacity to handle legitimate traffic.
Mitigation strategies for CVE-2002-0990 should focus on implementing connection rate limiting, DNS resolution timeouts, and resource management controls within the affected Symantec products. Organizations should apply the vendor-provided security patches and updates as soon as they become available, as these typically address the resource management deficiencies in the proxy component. Network administrators should configure connection limits and implement connection pooling mechanisms to prevent resource exhaustion. The implementation of DNS caching solutions and proper DNS resolution timeouts can help mitigate the impact of unresponsive DNS servers. Security monitoring should be enhanced to detect unusual connection patterns and resource consumption spikes that may indicate exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to tactics involving resource exhaustion and denial of service, specifically T1499.004 for network denial of service and T1566.002 for phishing with malicious attachments or links. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of such attacks. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar resource management weaknesses in other security infrastructure components. The vulnerability highlights the importance of proper error handling and resource management in security products, emphasizing the need for robust defensive programming practices and comprehensive testing of failure scenarios.