CVE-2019-2749 in Oracle
Summary
by MITRE
Vulnerability in the Java VM component of Oracle Database Server. Supported versions that are affected are 11.2.0.4, 12.1.0.2, 12.2.0.1, 18c and 19c. Difficult to exploit vulnerability allows low privileged attacker having Create Session, Create Procedure privilege with network access via multiple protocols to compromise Java VM. Successful attacks of this vulnerability can result in unauthorized creation, deletion or modification access to critical data or all Java VM accessible data and unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Java VM. CVSS 3.0 Base Score 6.8 (Integrity and Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H).
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Analysis
by VulDB Data Team • 07/05/2020
The vulnerability described in CVE-2019-2749 represents a significant security weakness within Oracle Database Server's Java Virtual Machine component, specifically affecting versions 11.2.0.4, 12.1.0.2, 12.2.0.1, 18c, and 19c. This flaw resides in the Java VM execution environment that Oracle Database uses to process Java-based applications and stored procedures, creating a potential attack surface that could be exploited by malicious actors with minimal privileges. The vulnerability's classification as difficult to exploit indicates that while the attack requires some level of preparation and understanding, the actual execution mechanism is relatively straightforward once the initial access vector is established.
The technical nature of this vulnerability stems from insufficient input validation within the Java VM component, allowing attackers to manipulate the execution flow through carefully crafted inputs. The flaw specifically enables low-privileged users who possess basic database session creation and procedure creation privileges to gain unauthorized access to Java VM functionality. This represents a privilege escalation vector where minimal database permissions can be leveraged to achieve broader system compromise. The vulnerability's impact extends beyond simple data manipulation to include complete denial of service conditions, where attackers can cause the Java VM to hang or crash repeatedly, effectively rendering the database's Java execution capabilities unusable.
From an operational standpoint, the implications of CVE-2019-2749 are particularly concerning as it affects the integrity and availability aspects of the database system. The vulnerability allows attackers to create, delete, or modify critical data within the Java VM accessible environment, potentially compromising sensitive information stored within database applications. The availability impact is severe as successful exploitation can result in complete system downtime through repeated crashes or hangs of the Java VM process. This vulnerability particularly affects organizations that rely heavily on Java-based database applications and stored procedures, as it undermines the fundamental security assumptions of database privilege management.
The attack vector for this vulnerability requires network access and targets the Java VM component through multiple protocols, indicating that the flaw exists at a protocol level rather than being limited to specific communication channels. This multi-protocol nature increases the exploitability potential as attackers can leverage various network interfaces and communication methods to reach the vulnerable component. Organizations should consider implementing network segmentation and access controls to limit exposure, particularly for database systems that execute Java applications. The CVSS score of 6.8 reflects the moderate to high severity of this vulnerability, with the integrity and availability impacts being particularly significant.
Mitigation strategies should focus on immediate patching of affected Oracle Database versions, as well as implementing network-level controls to restrict access to database Java VM components. Database administrators should review and restrict user privileges, particularly those related to procedure creation and session management. The vulnerability aligns with CWE-20, which describes improper input validation, and represents a classic example of how insufficient validation in trusted code components can lead to privilege escalation and system compromise. Organizations should also consider implementing monitoring and alerting for unusual Java VM activity and network access patterns to detect potential exploitation attempts.
The ATT&CK framework categorizes this vulnerability under privilege escalation and denial of service techniques, as attackers can leverage minimal database permissions to achieve system-wide impacts. The vulnerability demonstrates how database security controls can be bypassed through targeted exploitation of component-level weaknesses, emphasizing the importance of comprehensive security assessments that consider all database components including Java VM execution environments. Organizations should prioritize patch management for Oracle Database installations and implement regular security assessments to identify and remediate similar vulnerabilities in their database infrastructure.
This vulnerability highlights the critical importance of securing database application execution environments, particularly those that support Java-based applications and stored procedures. The flaw demonstrates how database security boundaries can be crossed through component-level vulnerabilities, affecting both data integrity and system availability. Organizations should maintain current threat intelligence on database vulnerabilities and ensure comprehensive testing of security controls before implementing database changes or updates. The multi-version impact of this vulnerability across Oracle Database releases underscores the need for coordinated patch management and security monitoring across all database systems in an organization's infrastructure.