CVE-2001-0513 in Oracle9i
Summary
by MITRE
Oracle listener process on Windows NT redirects connection requests to another port and creates a separate thread to process the request, which allows remote attackers to cause a denial of service by repeatedly connecting to the Oracle listener but not connecting to the redirected port.
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Analysis
by VulDB Data Team • 12/15/2024
The vulnerability identified as CVE-2001-0513 affects Oracle listener processes running on Windows NT systems, representing a significant denial of service weakness that exploits the listener's connection handling mechanism. This flaw resides in the Oracle database listener component that manages client connections to the database service, specifically manifesting when the listener receives connection requests and redirects them to alternative ports while maintaining separate threads for processing. The issue stems from the listener's behavior of creating new threads for each redirected connection request without proper validation or connection state management, creating a pathway for malicious exploitation through resource exhaustion attacks.
The technical implementation of this vulnerability demonstrates a classic resource consumption attack pattern where remote adversaries can repeatedly establish connections to the Oracle listener without ever completing the connection to the redirected port. This creates a scenario where the listener process maintains numerous active threads in a pending state, each consuming system resources including memory and processor time. The flaw operates at the application layer of the network stack, specifically affecting the listener's protocol handling and connection management functions, which aligns with CWE-400, indicating an improper handling of resources that leads to denial of service conditions. The vulnerability is particularly dangerous because it does not require authentication or specialized privileges to exploit, making it accessible to any remote attacker who can reach the Oracle listener port.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire database availability and system stability. When exploited successfully, the vulnerability can cause the Oracle listener process to consume excessive system resources, leading to complete denial of service for legitimate database connections. This attack vector particularly affects enterprise environments where Oracle databases are critical infrastructure components, as it can result in extended downtime for database services and potentially impact business operations. The vulnerability's exploitation aligns with ATT&CK technique T1499.004, which describes the use of resource exhaustion attacks to deny service to legitimate users. Organizations with multiple Oracle installations across their network infrastructure may experience cascading failures if the listener processes are not properly protected, as the attack can be amplified through network scanning and automated exploitation tools.
Mitigation strategies for CVE-2001-0513 should focus on both immediate protective measures and long-term architectural improvements to database security. System administrators should implement connection rate limiting and connection timeout configurations within the Oracle listener settings to prevent unlimited thread creation and resource consumption. Network-level protections including firewall rules and access control lists can restrict access to Oracle listener ports to trusted IP addresses only, reducing the attack surface. The implementation of Oracle's built-in security features such as the listener log configuration and connection monitoring can help detect and respond to exploitation attempts. Additionally, organizations should consider upgrading to newer versions of Oracle software where this vulnerability has been addressed through improved connection handling mechanisms and better resource management. Regular security assessments and monitoring of listener processes for unusual connection patterns can help identify potential exploitation attempts before they cause significant disruption. The vulnerability also highlights the importance of maintaining current security patches and implementing proper network segmentation to isolate critical database services from general network access.