CVE-2018-2639 in Java SE
Summary
by MITRE
Vulnerability in the Java SE component of Oracle Java SE (subcomponent: Deployment). Supported versions that are affected are Java SE: 8u152 and 9.0.1. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Java SE. Successful attacks require human interaction from a person other than the attacker and while the vulnerability is in Java SE, attacks may significantly impact additional products. Successful attacks of this vulnerability can result in takeover of Java SE. Note: This vulnerability applies to Java deployments, typically in clients running sandboxed Java Web Start applications or sandboxed Java applets, that load and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for security. This vulnerability does not apply to Java deployments, typically in servers, that load and run only trusted code (e.g., code installed by an administrator). CVSS 3.0 Base Score 8.3 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H).
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Analysis
by VulDB Data Team • 01/31/2021
This vulnerability resides within the Java SE deployment component and represents a critical security flaw affecting Java SE versions 8u152 and 9.0.1. The vulnerability operates through a sophisticated attack vector that requires network access via multiple protocols, making it particularly dangerous in modern networked environments where Java applications are frequently executed. The CVSS 3.0 score of 8.3 indicates high severity across all impact categories including confidentiality, integrity, and availability, with the attack complexity rated as high and requiring human interaction for successful exploitation.
The technical flaw manifests in the Java sandbox mechanism that is designed to isolate untrusted code execution. When Java Web Start applications or Java applets load untrusted code from the internet, the sandbox should provide adequate security boundaries. However, this vulnerability allows attackers to bypass these security controls, effectively undermining the fundamental security model that protects users from malicious code execution. The vulnerability specifically targets deployments in client environments rather than server environments, where trusted code is typically executed, making client-side Java applications particularly vulnerable.
The operational impact of this vulnerability extends beyond simple compromise of the Java SE component itself. As noted in the vulnerability description, successful exploitation can result in complete takeover of the Java SE environment, which may then serve as a launching point for broader attacks against the underlying system. The requirement for human interaction means that attackers must trick users into executing malicious Java content, often through social engineering techniques targeting web browsers or email attachments. This human factor makes the vulnerability particularly challenging to defend against since it requires user awareness and caution rather than purely technical controls.
Security practitioners should recognize this vulnerability as aligned with CWE-254, which addresses security weaknesses in the Java sandbox mechanism, and it maps to ATT&CK technique T1059.007 for application execution through Java. The vulnerability demonstrates how sandbox mechanisms can be circumvented when underlying components contain implementation flaws that allow privilege escalation or code injection attacks. Organizations running Java-based applications in client environments must implement immediate mitigations including disabling Java plugin support in web browsers, implementing strict network access controls, and deploying application whitelisting solutions. The vulnerability also underscores the importance of maintaining current Java installations and implementing proper security awareness training to prevent social engineering attacks that could lead to successful exploitation.