CVE-2021-2135 in WebLogic Server
Summary
by MITRE • 04/23/2021
Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: Coherence Container). Supported versions that are affected are 12.1.3.0.0, 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 takeover of Oracle WebLogic Server. CVSS 3.1 Base Score 9.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/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 • 04/25/2021
The vulnerability identified as CVE-2021-2135 represents a critical security flaw within Oracle WebLogic Server's Coherence Container component, specifically affecting versions 12.1.3.0.0, 12.2.1.3.0, 12.2.1.4.0, and 14.1.1.0.0. This vulnerability resides within Oracle Fusion Middleware and demonstrates the inherent risks associated with enterprise application servers that handle complex distributed computing operations. The Coherence Container serves as a critical component for managing distributed caching and data grids within WebLogic Server environments, making it a prime target for attackers seeking to compromise enterprise infrastructure. The vulnerability's classification as easily exploitable indicates that attackers can leverage this flaw without requiring specialized skills or privileged access, significantly amplifying its potential impact across enterprise networks.
The technical nature of this vulnerability allows unauthenticated attackers to exploit network access through T3 and IIOP protocols, which are fundamental communication channels used by WebLogic Server for client-server interactions and distributed object communication. T3 protocol operates on TCP port 7001 by default and provides a binary communication interface for WebLogic Server clients, while IIOP (Internet Inter-ORB Protocol) enables interoperability between different object request brokers in distributed systems. The flaw permits attackers to execute arbitrary code on the target server without authentication, effectively bypassing traditional access controls that should protect enterprise applications. This represents a severe weakness in the server's security architecture, as it eliminates the need for legitimate credentials or network-level authentication, enabling attackers to directly compromise the server's operational integrity.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as successful exploitation can lead to complete server takeover and subsequent compromise of the entire enterprise infrastructure. Attackers who successfully exploit this vulnerability gain full control over the WebLogic Server instance, enabling them to execute malicious code, modify configurations, access sensitive data, and potentially establish persistence within the network. The CVSS 3.1 base score of 9.8 reflects the severity of this flaw, indicating high impact across confidentiality, integrity, and availability domains. This comprehensive impact assessment suggests that attackers can not only read sensitive information stored within the server but also modify or delete critical data while potentially disrupting service availability through various attack vectors. The vulnerability's potential for lateral movement within enterprise networks makes it particularly dangerous for organizations relying on WebLogic Server for mission-critical applications.
Organizations affected by this vulnerability should implement immediate mitigations including network segmentation to restrict access to T3 and IIOP ports, firewall rule configuration to limit exposure, and mandatory patching of affected server versions. The vulnerability aligns with CWE-284 (Improper Access Control) and CWE-915 (Improperly Controlled Modification of Dynamically-Loaded Code) categories, reflecting both access control failures and code modification vulnerabilities. From an ATT&CK framework perspective, this vulnerability maps to T1190 (Exploit Public-Facing Application) and T1059 (Command and Scripting Interpreter) techniques, as attackers can exploit public-facing applications to gain access and then execute commands on compromised systems. Organizations should also consider implementing network monitoring solutions to detect unauthorized T3 and IIOP traffic, as well as regular vulnerability assessments to identify similar exposure points within their enterprise infrastructure. The vulnerability underscores the critical importance of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect against sophisticated attacks targeting enterprise application servers.