CVE-2019-2786 in Java SE
Summary
by MITRE
Vulnerability in the Java SE, Java SE Embedded component of Oracle Java SE (subcomponent: Security). Supported versions that are affected are Java SE: 8u212, 11.0.3 and 12.0.1; Java SE Embedded: 8u211. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Java SE, Java SE Embedded. Successful attacks require human interaction from a person other than the attacker and while the vulnerability is in Java SE, Java SE Embedded, attacks may significantly impact additional products. Successful attacks of this vulnerability can result in unauthorized read access to a subset of Java SE, Java SE Embedded accessible data. Note: This vulnerability applies to Java deployments, typically in clients running sandboxed Java Web Start applications or sandboxed Java applets (in Java SE 8), that load and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for security. This vulnerability can also be exploited by using APIs in the specified Component, e.g., through a web service which supplies data to the APIs. CVSS 3.0 Base Score 3.4 (Confidentiality impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N).
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Analysis
by VulDB Data Team • 07/06/2020
The vulnerability identified as CVE-2019-2786 resides within Oracle Java SE and Java SE Embedded security components, specifically affecting versions 8u212, 11.0.3, and 12.0.1 for Java SE, along with 8u211 for Java SE Embedded. This vulnerability represents a significant concern for organizations relying on Java-based applications, particularly those deployed in client environments where sandboxed applications execute untrusted code. The issue manifests as a difficulty in exploitation but remains a substantial risk due to its potential to allow unauthorized data access through network-based attacks. The CVSS 3.0 score of 3.4 indicates a low to medium severity classification, yet the implications extend beyond simple confidentiality impacts given the nature of Java's sandboxed execution environment and the potential for cascading effects across multiple products. The vulnerability's classification under CWE-284 (Improper Access Control) and its mapping to ATT&CK technique T1068 (Exploitation for Privilege Escalation) demonstrates how this flaw can be leveraged to bypass security controls within Java applications.
The technical flaw involves a weakness in the Java Security component that permits unauthorized read access to a subset of data within Java SE and Java SE Embedded environments. This vulnerability specifically targets the sandboxing mechanisms that Java employs to isolate untrusted code execution, particularly in scenarios where Java Web Start applications or applets load code from untrusted sources such as the internet. The attack requires an unauthenticated network connection and necessitates human interaction from users who are not the attackers themselves, typically involving users clicking on malicious links or downloading compromised content. The exploit process involves leveraging APIs within the affected component, potentially through web services that provide data to these APIs, making it particularly dangerous in environments where web services are prevalent. The vulnerability's impact is mitigated by the requirement for user interaction, but this also means that social engineering attacks could easily leverage this weakness, making it particularly dangerous in enterprise environments where user awareness may be insufficient.
The operational impact of CVE-2019-2786 extends beyond simple data confidentiality breaches, as it can compromise the fundamental security model that Java applications rely upon for protection. Organizations running Java applications in client environments, particularly those using Java Web Start or applet-based deployments, face significant risks from this vulnerability. The fact that this vulnerability affects multiple Java versions simultaneously means that organizations must carefully evaluate their entire Java deployment landscape to identify all potentially affected systems. The attack vector through multiple protocols and the requirement for human interaction through legitimate user activities makes this vulnerability particularly insidious, as it can be exploited through seemingly normal user behavior patterns. This vulnerability's potential to impact additional products beyond just Java SE and Java SE Embedded indicates that organizations should consider the broader ecosystem implications, as compromised Java applications may provide attackers with access to other systems or data within the network infrastructure. The low complexity to exploit and the ability to achieve unauthorized read access make this vulnerability particularly attractive to threat actors targeting enterprise environments where Java applications are prevalent.
Mitigation strategies for CVE-2019-2786 should prioritize immediate patching of all affected Java SE and Java SE Embedded installations to the latest available versions. Organizations should implement network segmentation and monitoring to detect unusual network traffic patterns that might indicate exploitation attempts, particularly focusing on connections to known malicious domains or services. The principle of least privilege should be enforced by restricting Java application execution capabilities, particularly in environments where untrusted code is loaded. Security awareness training should be implemented to educate users about the risks of interacting with untrusted content, as the vulnerability requires human interaction to be successfully exploited. Additional controls such as web application firewalls, network access controls, and application whitelisting can provide defense-in-depth measures. Organizations should also consider disabling Java applets and Web Start applications where possible, as these deployment methods are particularly vulnerable to this type of attack. Regular vulnerability assessments and penetration testing should be conducted to identify and remediate similar vulnerabilities within the Java ecosystem, ensuring that the security posture remains robust against evolving threats. The vulnerability's mapping to ATT&CK technique T1068 emphasizes the need for comprehensive threat hunting activities that focus on privilege escalation and access control bypass techniques.