CVE-2021-2018 in Database Server
Summary
by MITRE • 01/20/2021
Vulnerability in the Advanced Networking Option component of Oracle Database Server. Supported versions that are affected are 18c and 19c. Difficult to exploit vulnerability allows unauthenticated attacker with network access via Oracle Net to compromise Advanced Networking Option. Successful attacks require human interaction from a person other than the attacker and while the vulnerability is in Advanced Networking Option, attacks may significantly impact additional products. Successful attacks of this vulnerability can result in takeover of Advanced Networking Option. Note: CVE-2021-2018 affects Windows platform only. CVSS 3.1 Base Score 8.3 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H).
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Analysis
by VulDB Data Team • 02/15/2021
The vulnerability described in CVE-2021-2018 represents a critical security flaw within Oracle Database Server's Advanced Networking Option component affecting versions 18c and 19c specifically on Windows platforms. This vulnerability resides in the Oracle Net protocol implementation which serves as the network communication layer for database connections. The flaw manifests as a remote code execution vulnerability that can be exploited by unauthenticated attackers who gain network access to the target system. The CVSS score of 8.3 indicates a high-severity threat with significant impacts across confidentiality, integrity, and availability domains. The vulnerability's classification as difficult to exploit suggests that while the attack vector exists, specific conditions must be met for successful compromise, though the potential impact remains severe.
The technical nature of this vulnerability stems from improper input validation within the Advanced Networking Option functionality, which processes network requests from clients. This flaw allows an attacker to craft malicious network packets that can trigger unexpected behavior in the database server's networking stack. The requirement for human interaction indicates that while the initial exploit may be automated, some form of user involvement or specific system state is necessary to complete the attack chain. The vulnerability's impact extends beyond the immediate Advanced Networking Option component, potentially affecting other Oracle products due to the interconnected nature of database server components. This cascading effect aligns with the Common Weakness Enumeration CWE-121 which categorizes buffer overflow vulnerabilities that can lead to arbitrary code execution.
From an operational perspective, successful exploitation of CVE-2021-2018 can result in complete compromise of the Advanced Networking Option functionality, potentially allowing attackers to execute arbitrary code with the privileges of the database service account. The attack requires network access via Oracle Net, which means that systems exposed to untrusted networks or without proper network segmentation are at heightened risk. The vulnerability's Windows-specific nature means that organizations running Oracle Database on Windows servers must prioritize patching and mitigation efforts, as the attack surface is more limited compared to other operating systems. The CVSS vector indicates that while the attack requires high complexity (AC:H) and user interaction (UI:R), the potential for significant damage makes this vulnerability particularly concerning for enterprise environments.
Organizations should implement multiple layers of defense to protect against exploitation of this vulnerability. Network segmentation and firewall rules should restrict access to Oracle Net ports to trusted networks only, while regular patch management processes must be established to ensure timely deployment of Oracle security updates. The vulnerability's classification under the ATT&CK framework would likely map to techniques such as T1190 (Exploit Public-Facing Application) and T1059 (Command and Scripting Interpreter) as attackers attempt to establish persistent access. Additionally, monitoring network traffic for unusual Oracle Net protocol patterns and implementing intrusion detection systems can help identify potential exploitation attempts. Database administrators should also consider disabling unnecessary network protocols and implementing strong authentication mechanisms to reduce the attack surface. The vulnerability demonstrates the importance of maintaining up-to-date security patches and following the principle of least privilege when configuring database server environments.