CVE-2023-21838 in WebLogic Server
Summary
by MITRE • 01/18/2023
Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: Core). Supported versions that are affected are 12.2.1.3.0, 12.2.1.4.0 and 14.1.1.0.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via T3, IIOP to compromise Oracle WebLogic Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle WebLogic Server. CVSS 3.1 Base Score 7.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 09/17/2024
The vulnerability identified as CVE-2023-21838 represents a critical availability flaw within Oracle WebLogic Server, specifically within the Core component of Oracle Fusion Middleware. This vulnerability affects multiple supported versions including 12.2.1.3.0, 12.2.1.4.0, and 14.1.1.0.0, making it a widespread concern for organizations utilizing these server configurations. The vulnerability resides in the server's handling of incoming network connections through T3 and IIOP protocols, which are commonly used for Java Remote Method Invocation and CORBA communication respectively. The attack vector requires only network access without any authentication requirements, making it particularly dangerous as it can be exploited by any remote attacker who can reach the target server.
The technical nature of this vulnerability allows for a complete denial of service condition where an unauthenticated attacker can cause the WebLogic Server to hang or repeatedly crash, effectively rendering the service unavailable to legitimate users. This occurs through the manipulation of T3 and IIOP protocol communications, which are fundamental to the server's operation and inter-process communication capabilities. The vulnerability's classification as easily exploitable indicates that the attack mechanism requires minimal technical skill or resources to execute successfully, making it a significant risk for organizations with exposed WebLogic Server instances. The CVSS score of 7.5 reflects the high availability impact with no requirements for user interaction or privilege escalation, while the attack complexity is rated as low, meaning the exploitation can be accomplished with minimal effort.
The operational impact of CVE-2023-21838 extends beyond simple service disruption to potentially causing substantial business interruption and financial loss. Organizations relying on WebLogic Server for critical applications may experience extended downtime during exploitation attempts, leading to productivity losses, customer service degradation, and potential revenue impact. The vulnerability's ability to cause repeated crashes means that even brief exploitation periods could result in extended system recovery times and service restoration efforts. This vulnerability particularly affects environments where WebLogic Server is exposed to untrusted networks or where proper network segmentation has not been implemented to isolate the server from external threats.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected versions to address the underlying protocol handling flaws. Organizations should implement network segmentation to restrict access to WebLogic Server instances, particularly disabling T3 and IIOP protocols where they are not strictly required for business operations. Network access control lists should be configured to limit exposure of the server to trusted networks only, while monitoring systems should be enhanced to detect anomalous protocol usage patterns. The vulnerability aligns with CWE-119 which addresses improper restriction of operations within a limited context, and relates to ATT&CK technique T1499 which covers network denial of service attacks. Additionally, implementing proper firewall rules to block unnecessary ports and protocols, conducting regular vulnerability assessments, and maintaining updated security monitoring tools are essential defensive measures that should be implemented immediately to protect against exploitation of this vulnerability.