CVE-2019-2956 in Database Server
Summary
by MITRE
Vulnerability in the Core RDBMS (jackson-databind) 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 multiple protocols to compromise Core RDBMS (jackson-databind). Successful attacks require human interaction from a person other than the attacker. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Core RDBMS (jackson-databind). CVSS 3.0 Base Score 5.7 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 01/09/2024
The vulnerability identified as CVE-2019-2956 resides within the Core RDBMS component of Oracle Database Server, specifically affecting the jackson-databind library which is a widely used JSON processing library in Java applications. This vulnerability impacts Oracle Database versions 12.1.0.2, 12.2.0.1, 18c, and 19c, making it a significant concern for organizations maintaining these database versions. The flaw is classified as easily exploitable, requiring only a low privileged attacker who possesses the Create Session privilege, indicating that the vulnerability can be leveraged by users with minimal database permissions. The attack vector involves network access through multiple protocols, suggesting that the vulnerability can be exploited across different communication channels that the database server supports.
The technical nature of this vulnerability stems from improper input validation within the jackson-databind library implementation, which allows maliciously crafted JSON data to trigger unexpected behavior in the database's processing mechanisms. The CVSS score of 5.7 with a base vector of AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H indicates a medium severity issue that requires low complexity to exploit, only low privilege access, and human interaction from someone other than the attacker. The availability impact is rated as high, with the potential to cause complete denial of service through hangs or frequently repeatable crashes of the Core RDBMS component. This type of vulnerability falls under CWE-20, which represents "Improper Input Validation," and aligns with ATT&CK techniques related to denial of service through resource exhaustion or process manipulation.
The operational impact of this vulnerability extends beyond simple service disruption as it can lead to complete system unavailability for database operations. When exploited successfully, the vulnerability can cause the jackson-databind component to enter a state where it repeatedly crashes or becomes unresponsive, effectively rendering database services unavailable to legitimate users. This situation is particularly concerning in enterprise environments where database availability is critical for business operations, as it can lead to significant downtime and potential data access issues. The requirement for human interaction from a person other than the attacker suggests that while the initial exploitation may be automated, some form of user involvement is necessary to complete the attack chain, potentially indicating a social engineering component or the need for specific user actions to trigger the vulnerable code path.
Organizations affected by this vulnerability should prioritize immediate mitigation through Oracle's security patches and updates, as the vulnerability affects multiple supported database versions. The recommended approach includes applying the appropriate Oracle Critical Patch Updates or interim patches that address the jackson-databind processing flaw. Additionally, network segmentation and access controls should be reviewed to limit the potential attack surface, particularly ensuring that only authorized users with legitimate business needs have Create Session privileges. Monitoring and logging should be enhanced to detect unusual patterns in database connections and JSON data processing activities that might indicate exploitation attempts. The vulnerability's classification as a denial of service issue also necessitates robust backup and recovery procedures to minimize the impact of potential service disruptions, while network administrators should consider implementing rate limiting and input validation measures to prevent exploitation attempts from reaching the vulnerable database components.