CVE-2023-21996 in WebLogic Server
Summary
by MITRE • 04/18/2023
Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: Web Services). 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 HTTP 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 • 05/11/2023
The vulnerability identified as CVE-2023-21996 represents a critical availability-focused weakness within Oracle WebLogic Server's Web Services component. This flaw exists in multiple supported versions including 12.2.1.3.0, 12.2.1.4.0, and 14.1.1.0.0, making it particularly concerning for organizations maintaining these server configurations. The vulnerability's classification as easily exploitable indicates that attackers require minimal prerequisites to leverage this weakness, essentially requiring only network connectivity through HTTP protocols. This accessibility significantly broadens the potential attack surface and increases the likelihood of successful exploitation across various network environments.
The technical nature of this vulnerability stems from insufficient input validation within the Web Services component of Oracle WebLogic Server, creating an avenue for malicious actors to craft specific HTTP requests that trigger abnormal server behavior. When exploited, the vulnerability enables attackers to induce a complete denial of service condition that can either cause the server to hang indefinitely or repeatedly crash in a manner that renders the service unavailable to legitimate users. The underlying mechanism typically involves malformed input processing that fails to properly sanitize or validate incoming web service requests, allowing crafted payloads to disrupt normal server operations. This type of vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and may also relate to CWE-471, concerning the use of non-constant strings in security-sensitive contexts.
The operational impact of CVE-2023-21996 extends beyond simple service disruption to potentially compromise business continuity and operational availability. Organizations relying on Oracle WebLogic Server for critical enterprise applications face significant risk of service outages that can cascade through dependent systems and applications. The CVSS 3.1 base score of 7.5 reflects the high availability impact and low complexity required for exploitation, indicating that even novice attackers can potentially cause substantial disruption. This vulnerability particularly affects environments where WebLogic Server serves as a core component of enterprise infrastructure, potentially impacting financial services, healthcare systems, government platforms, and other mission-critical deployments where continuous availability is essential. The complete denial of service condition can result in extended downtime that may require manual intervention to restore service, potentially causing significant financial and operational losses.
Organizations must implement immediate mitigation strategies to address this vulnerability, beginning with applying the relevant Oracle Critical Patch Updates that contain patches for this specific flaw. Network segmentation and firewall rules should be configured to restrict unnecessary HTTP access to WebLogic Server instances, particularly limiting exposure to trusted networks only. Implementing intrusion detection systems and monitoring for anomalous HTTP request patterns can help identify potential exploitation attempts. Additionally, organizations should consider deploying application firewalls or web application firewalls that can filter malicious requests before they reach the vulnerable Web Services component. The mitigation approach should also include regular security assessments of WebLogic Server configurations to ensure that no unnecessary services or components remain exposed. According to ATT&CK framework, this vulnerability aligns with T1499.004 which covers network denial of service attacks, and organizations should prepare incident response procedures that specifically address availability-focused attacks targeting middleware platforms. Regular vulnerability scanning and penetration testing should be conducted to identify similar weaknesses in the broader application ecosystem, as this vulnerability may indicate broader security gaps in the organization's infrastructure security posture.