CVE-2016-5549 in Java SE
Summary
by MITRE
Vulnerability in the Java SE, Java SE Embedded component of Oracle Java SE (subcomponent: Libraries). Supported versions that are affected are Java SE: 7u121 and 8u112; Java SE Embedded: 8u111. Easily exploitable 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. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all 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, 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 v3.0 Base Score 6.5 (Confidentiality impacts).
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Analysis
by VulDB Data Team • 05/15/2026
This vulnerability resides within the Java SE and Java SE Embedded platforms, specifically affecting the Libraries subcomponent of Oracle's Java runtime environment. The flaw manifests in versions Java SE 7u121 and 8u112, along with Java SE Embedded 8u111, representing a significant security gap that enables unauthenticated attackers to compromise systems through network-based exploitation. The vulnerability's classification as easily exploitable indicates that attackers require minimal technical expertise to leverage this weakness, making it particularly dangerous in production environments where Java applications are commonly deployed. The attack vector operates through multiple protocols, allowing adversaries to exploit the vulnerability from remote locations without requiring prior authentication credentials.
The technical nature of this vulnerability stems from insufficient validation mechanisms within the Java runtime libraries, creating opportunities for attackers to bypass security restrictions that normally protect against unauthorized data access. The requirement for human interaction from individuals other than the attacker suggests that social engineering or user manipulation may be necessary to initiate the attack sequence, though this does not significantly reduce the overall risk level. This characteristic aligns with attack patterns documented in the ATT&CK framework under initial access and privilege escalation techniques, where user interaction often serves as a critical enabling factor for successful exploitation. The vulnerability's impact extends to critical data compromise and complete access to all Java SE and Java SE Embedded accessible data, representing a severe confidentiality breach that could result in substantial information loss.
The operational impact of this vulnerability is particularly concerning for organizations running sandboxed Java Web Start applications or applets that process untrusted code from internet sources. These deployment scenarios represent the primary attack surface where the vulnerability can be effectively exploited, as they rely on Java's sandbox security model to protect against malicious code execution. Systems that load and execute only trusted code, such as server-side deployments managed by administrators, remain unaffected by this specific vulnerability. The CVSS v3.0 base score of 6.5 indicates a medium to high severity rating, with the confidentiality impact being the primary concern. This vulnerability directly relates to CWE-284, which addresses improper access control in software systems, and aligns with ATT&CK techniques focused on privilege escalation and credential access through application-level vulnerabilities. Organizations using Java-based applications in client environments must prioritize immediate remediation to prevent potential data breaches and unauthorized system access.
The remediation approach requires immediate deployment of Oracle's security patches for the affected Java SE versions, specifically addressing the library component vulnerabilities that enable this exploitation path. System administrators should conduct comprehensive vulnerability assessments to identify all Java installations that may be exposed to this attack vector, particularly focusing on client systems that execute sandboxed web applications. Network segmentation and firewall rules should be implemented to limit unnecessary access to Java-enabled systems, while user education programs should emphasize the dangers of executing untrusted code from unknown sources. Regular security monitoring and intrusion detection systems should be configured to detect potential exploitation attempts targeting this specific vulnerability, as the attack patterns may evolve over time. Organizations should also consider implementing additional security controls such as Java security policy restrictions and code signing verification to provide defense-in-depth against similar future vulnerabilities.