CVE-2019-2856 in WebLogic Server
Summary
by MITRE
Vulnerability in the Oracle WebLogic Server component of Oracle Fusion Middleware (subcomponent: Application Container - JavaEE). Supported versions that are affected is 12.2.1.3.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via T3 to compromise Oracle WebLogic Server. Successful attacks of this vulnerability can result in takeover of Oracle WebLogic Server. CVSS 3.0 Base Score 9.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
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Analysis
by VulDB Data Team • 07/06/2020
The vulnerability identified as CVE-2019-2856 represents a critical security flaw within Oracle WebLogic Server's Application Container component, specifically affecting version 12.2.1.3.0. This vulnerability resides within the JavaEE application container subsystem of Oracle Fusion Middleware, making it a prime target for attackers seeking to compromise enterprise web infrastructure. The flaw manifests through the T3 protocol implementation, which is a proprietary Oracle protocol used for communication between WebLogic Server instances and clients. The vulnerability's classification as easily exploitable indicates that attackers require minimal prerequisites to leverage this weakness, essentially eliminating the need for specialized tools or extensive reconnaissance. The CVSS 3.0 score of 9.8 reflects the severity of impact across confidentiality, integrity, and availability domains, demonstrating the potential for complete system compromise without authentication requirements.
The technical exploitation mechanism of CVE-2019-2856 leverages the T3 protocol's deserialization functionality, which allows remote code execution when processing maliciously crafted serialized objects. Attackers can send specially crafted T3 protocol messages to the vulnerable WebLogic Server instance, triggering a deserialization process that executes arbitrary code with the privileges of the WebLogic Server process. This vulnerability falls under CWE-502, which specifically addresses "Deserialization of Untrusted Data," making it a classic example of insecure deserialization attacks. The attack vector requires only network access to the T3 port, typically port 7001 or other configured ports, making it particularly dangerous in environments where these ports are exposed to untrusted networks. The lack of authentication requirements means that any attacker with network access can potentially exploit this vulnerability, significantly increasing the attack surface and risk exposure.
The operational impact of successful exploitation extends far beyond simple unauthorized access, as the vulnerability provides attackers with complete control over the compromised WebLogic Server instance. This level of compromise allows adversaries to execute arbitrary commands, access sensitive data, modify system configurations, and potentially use the compromised server as a pivot point for attacking other systems within the network infrastructure. The confidentiality impact is severe as attackers can extract sensitive information stored within the application container, including database credentials, application data, and potentially enterprise intellectual property. The integrity impact is equally concerning as attackers can modify application behavior, inject malicious code into running applications, or corrupt system configurations. The availability impact means that attackers can potentially cause denial of service conditions or completely disable the WebLogic Server functionality, leading to business disruption and potential financial losses.
Organizations must implement immediate mitigations to address this vulnerability, including restricting network access to T3 ports through firewall rules and network segmentation to prevent unauthorized access from external networks. The most effective long-term solution involves applying Oracle's official security patches and updates, which address the underlying deserialization vulnerability in the WebLogic Server implementation. Network administrators should also consider disabling the T3 protocol entirely if it is not required for legitimate business operations, as this eliminates the attack surface associated with this vulnerable communication mechanism. Additionally, implementing network monitoring and intrusion detection systems can help identify suspicious T3 protocol traffic patterns that may indicate exploitation attempts. Security teams should conduct comprehensive vulnerability assessments to identify all instances of affected WebLogic Server versions and ensure proper patch management procedures are in place to prevent similar vulnerabilities from being exploited in the future. The ATT&CK framework categorizes this vulnerability under T1059 (Command and Scripting Interpreter) and T1105 (Ingress Tool Transfer) as attackers can leverage the compromised system to establish persistent access and exfiltrate data.