CVE-2001-0517 in Oracle8i
Summary
by MITRE
Oracle listener in Oracle 8i on Solaris allows remote attackers to cause a denial of service via a malformed connection packet with a maximum transport data size that is set to 0.
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Analysis
by VulDB Data Team • 05/31/2018
The vulnerability identified as CVE-2001-0517 affects Oracle 8i database listener components running on Solaris operating systems, representing a significant remote denial of service weakness that can be exploited by unauthorized attackers without requiring authentication credentials. This flaw resides within the Oracle listener service which is responsible for handling incoming database connection requests and managing communication between client applications and the database server. The vulnerability specifically targets the listener's processing of transport data size parameters within connection packets, creating a condition where malformed packets can trigger unexpected behavior in the system's network handling mechanisms.
The technical exploitation of this vulnerability occurs when a remote attacker crafts and sends a specially formatted connection packet to the Oracle listener service, deliberately setting the maximum transport data size field to zero. This seemingly innocuous value creates a critical processing error within the listener's network stack implementation, causing the service to enter an unstable state that ultimately results in system resource exhaustion or complete service termination. The flaw demonstrates poor input validation and error handling within the Oracle listener component, where the system fails to properly validate or reject malformed transport data size values that fall outside acceptable parameter ranges.
From an operational impact perspective, this vulnerability presents a substantial risk to database availability and business continuity, particularly in environments where Oracle 8i databases are critical to core operations. The remote nature of the attack means that adversaries can exploit this weakness from any location on the network without requiring physical access or prior authentication, making it particularly dangerous for organizations with exposed database listeners. The denial of service condition can persist until the affected listener service is manually restarted or the system is rebooted, potentially causing extended downtime that impacts database access for legitimate users and applications.
The vulnerability aligns with CWE-129, which addresses improper validation of input ranges, and demonstrates characteristics consistent with ATT&CK technique T1499.004 for network denial of service attacks. Organizations should implement immediate mitigations including applying Oracle's official security patches and updates, configuring network firewalls to restrict access to Oracle listener ports, and implementing monitoring solutions to detect unusual connection patterns or malformed packet traffic. Additionally, network segmentation strategies should be employed to limit direct exposure of Oracle listeners to untrusted networks, while regular security assessments should verify that listener services are properly configured with appropriate access controls and that all systems are running patched versions of Oracle software to prevent exploitation of this and similar vulnerabilities.