CVE-2020-2511 in Database Server
Summary
by MITRE
Vulnerability in the Core RDBMS component of Oracle Database Server. Supported versions that are affected are 12.1.0.2, 12.2.0.1, 18c and 19c. Easily exploitable vulnerability allows low privileged attacker having Create Session privilege with network access via OracleNet to compromise Core RDBMS. While the vulnerability is in Core RDBMS, attacks may significantly impact additional products. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Core RDBMS. CVSS 3.0 Base Score 7.7 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 03/21/2024
The vulnerability identified as CVE-2020-2511 resides within Oracle Database Server's Core RDBMS component, representing a significant security weakness that affects multiple supported versions including 12.1.0.2, 12.2.0.1, 18c, and 19c. This flaw operates at the core database engine level, making it particularly dangerous as it can be exploited by attackers with minimal privileges. The vulnerability's classification as easily exploitable indicates that the attack vector requires only basic network connectivity through OracleNet protocol and a relatively low privilege level, specifically the Create Session privilege which is commonly granted to standard database users. The CVSS 3.0 scoring system assigns this vulnerability a base score of 7.7, reflecting high availability impact and moderate exploitability characteristics, with the vector AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H indicating network-based exploitation with low attack complexity, low privilege requirements, and potential for catastrophic system-wide disruption.
The technical nature of this vulnerability stems from improper handling of certain database operations within the Core RDBMS, creating a condition where malicious input or specific sequence of operations can trigger a denial of service scenario. The flaw manifests as an inability to properly process certain network requests or database operations, leading to system instability that can result in complete system hangs or repeated crashes. This behavior directly impacts the availability aspect of the database system, as the affected Oracle Database instances become unresponsive and require manual intervention to restore service. The vulnerability's potential to cause complete system downtime represents a severe operational impact that can disrupt business continuity and data access for organizations relying on these database systems. The attack can be executed through standard network connections using OracleNet protocol, eliminating the need for specialized tools or complex attack chains that would typically be required for more sophisticated exploits.
The operational impact of CVE-2020-2511 extends beyond the immediate database server, as the vulnerability's influence can cascade to affect related Oracle products and integrated systems. This interconnected impact aligns with the CVSS scoring's scope change indicator S:C, demonstrating how a single vulnerability in the Core RDBMS can compromise broader Oracle ecosystem components that depend on database availability. Organizations may experience significant downtime, service interruptions, and potential data access restrictions that can affect multiple business applications and processes. The vulnerability's ability to cause frequently repeatable crashes makes it particularly challenging to manage, as it can be repeatedly triggered by attackers, maintaining sustained disruption to database services. Additionally, the fact that this vulnerability affects multiple versions simultaneously means that organizations must implement coordinated patching strategies across their entire Oracle Database deployment landscape, adding complexity to the remediation process and potentially creating service gaps during the patching window.
Mitigation strategies for CVE-2020-2511 should prioritize immediate implementation of Oracle's security patches and updates, as these address the root cause of the vulnerability. Organizations should also implement network segmentation and access controls to limit network access to Oracle Database servers, reducing the attack surface for potential exploitation. The principle of least privilege should be enforced, ensuring that database users only have the minimum required privileges necessary for their operations, thereby limiting potential attackers' ability to leverage this vulnerability. Network monitoring and intrusion detection systems should be configured to identify unusual database access patterns or potential exploitation attempts. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses within the database environment, while maintaining updated inventory records of all Oracle Database installations to ensure comprehensive coverage during patch management activities. The vulnerability's characteristics align with CWE-119, which addresses memory safety issues, and may also relate to ATT&CK techniques involving privilege escalation and denial of service attacks through database systems.