CVE-2021-35561 in Java SE
Summary
by MITRE • 10/20/2021
Vulnerability in the Java SE, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: Utility). Supported versions that are affected are Java SE: 7u311, 8u301, 11.0.12, 17; Oracle GraalVM Enterprise Edition: 20.3.3 and 21.2.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Java SE, Oracle GraalVM Enterprise Edition. Successful attacks of this vulnerability can result in unauthorized ability to cause a partial denial of service (partial DOS) of Java SE, Oracle GraalVM Enterprise Edition. 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 can also be exploited by using APIs in the specified Component, e.g., through a web service which supplies data to the APIs. CVSS 3.1 Base Score 5.3 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).
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Analysis
by VulDB Data Team • 10/13/2024
This vulnerability resides within the Java SE utility component of Oracle's Java platform and represents a significant security weakness that affects multiple Java versions including 7u311, 8u301, 11.0.12, and 17, as well as Oracle GraalVM Enterprise Edition versions 20.3.3 and 21.2.0. The flaw manifests as a partial denial of service condition that can be exploited by unauthenticated attackers who gain network access through various protocols. The vulnerability's exploitability score of 5.3 on the CVSS 3.1 scale indicates a moderate severity threat that specifically targets the availability aspect of the system's security posture. According to the Common Weakness Enumeration framework, this vulnerability aligns with CWE-225, which describes weaknesses related to improper handling of potentially dangerous input, particularly in contexts where untrusted code execution is possible. The attack vector analysis reveals that the threat primarily affects environments where Java Web Start applications or applets operate within sandboxed environments, creating a dangerous intersection between legitimate security boundaries and exploitable code execution paths.
The technical implementation of this vulnerability stems from inadequate validation mechanisms within the Java utility component that processes data from untrusted sources. Attackers can leverage this weakness to manipulate the Java runtime environment in ways that disrupt service availability without necessarily gaining full system compromise or executing malicious code directly. The vulnerability's impact extends beyond simple service disruption as it can be triggered through web services that supply data to affected APIs, making it particularly dangerous in enterprise environments where such interfaces are commonly used. The sandboxed nature of Java applets and Web Start applications creates an environment where attackers can exploit this weakness without requiring elevated privileges or authentication credentials, effectively bypassing traditional access control mechanisms. This characteristic places the vulnerability in the ATT&CK framework under the T1211 technique category, which involves exploitation of weaknesses in software components to achieve system compromise. The fact that this vulnerability can be exploited through multiple protocols indicates a fundamental flaw in the input validation and processing logic that affects various network communication channels.
The operational impact of this vulnerability creates substantial risk for organizations deploying Java-based applications in production environments, particularly those that rely on sandboxed execution models for security isolation. Organizations running affected Java versions may experience partial service disruption that could escalate into more severe availability issues if not addressed promptly. The vulnerability's ability to affect both standard Java SE deployments and Oracle GraalVM Enterprise Edition implementations means that security teams must consider multiple attack surfaces when implementing mitigation strategies. The security implications extend beyond immediate service availability concerns as this weakness could potentially be chained with other vulnerabilities to create more sophisticated attack vectors. Network administrators and security operations teams must understand that exploitation of this vulnerability does not require user interaction or privilege escalation, making it particularly dangerous in environments where Java applications are automatically executed from untrusted sources. The CVSS vector analysis indicates that the attack requires no user interaction and can be executed from any network location, making it a significant concern for organizations with exposed Java services. This vulnerability particularly affects organizations that deploy Java applets or Web Start applications in environments where network access is not properly restricted, as these deployment models create the exact conditions necessary for exploitation. The widespread nature of Java deployments across enterprise networks means that the potential attack surface for this vulnerability is extensive, requiring comprehensive vulnerability management and patching strategies.
Mitigation efforts should focus on immediate patching of affected Java versions to address the underlying validation weakness in the utility component. Organizations should implement network segmentation and access controls to limit exposure of Java applications to untrusted network traffic, particularly for environments running sandboxed Java applets or Web Start applications. Security teams must consider disabling or restricting the use of Java applets and Web Start functionality in environments where these technologies are not strictly required for business operations. The implementation of network monitoring and anomaly detection systems can help identify potential exploitation attempts by monitoring for unusual patterns in Java service behavior or network traffic originating from affected systems. Regular vulnerability assessments should include specific checks for Java versions that are impacted by this vulnerability, particularly in environments where legacy Java applications continue to operate. Organizations should also consider implementing application whitelisting policies that restrict which Java applications can execute on their systems, reducing the attack surface available to potential exploiters. The remediation process should include thorough testing of patched Java environments to ensure that security updates do not introduce compatibility issues with existing applications while maintaining the necessary security protections against this vulnerability. Additionally, organizations should review their Java deployment policies to ensure that only trusted code executes within sandboxed environments, and consider transitioning away from legacy Java technologies that are more prone to such vulnerabilities.