CVE-2001-0515 in Database Server
Summary
by MITRE
Oracle Listener in Oracle 7.3 and 8i allows remote attackers to cause a denial of service via a malformed connection packet with a large offset_to_data value.
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Analysis
by VulDB Data Team • 04/07/2017
The vulnerability identified as CVE-2001-0515 affects Oracle Listener components in Oracle Database versions 7.3 and 8i, representing a significant security weakness that enables remote attackers to execute denial of service attacks. This flaw resides within the network communication layer of Oracle's database infrastructure, specifically targeting the listener service that manages client connections to the database. The Oracle Listener acts as a mediator between client applications and database servers, making it a critical component in database architecture that requires robust security measures.
The technical implementation of this vulnerability stems from insufficient input validation within the connection packet processing mechanism. When a malformed connection packet is sent to the Oracle Listener, it contains an excessively large offset_to_data value that exceeds the expected parameters for data positioning within the packet structure. This improper validation allows attackers to manipulate the packet format in a way that causes the listener service to process invalid memory references or attempt to access data beyond the allocated buffer boundaries. The vulnerability operates at the protocol level where the listener expects specific formatting and data positioning, but the malformed packet disrupts normal operational flow through the oversized offset value.
The operational impact of this vulnerability extends beyond simple service disruption, as it can potentially lead to complete system unavailability and compromise database accessibility for legitimate users. When exploited, the malformed connection packet causes the Oracle Listener process to crash or become unresponsive, effectively preventing any new client connections from being established to the database server. This denial of service condition can persist until the listener service is manually restarted or the system is rebooted, creating significant operational downtime that can affect business continuity and database availability. The vulnerability is particularly concerning because it requires no authentication or specialized privileges to exploit, making it accessible to any remote attacker with network access to the database port.
Mitigation strategies for this vulnerability involve implementing proper input validation mechanisms and network segmentation to limit exposure to untrusted networks. Organizations should apply the appropriate Oracle security patches and updates that address this specific validation flaw in the listener component. Network administrators should consider implementing firewall rules to restrict access to Oracle listener ports from trusted networks only, while also monitoring for unusual connection patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-129, which addresses improper validation of length of input buffers, and relates to ATT&CK technique T1499.004, specifically targeting network denial of service through manipulation of network protocols. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues in database infrastructure components, while maintaining up-to-date security configurations and access controls to minimize the attack surface for such network-based exploits.