CVE-2018-2634 in Java SE
Summary
by MITRE
Vulnerability in the Java SE, Java SE Embedded component of Oracle Java SE (subcomponent: JGSS). Supported versions that are affected are Java SE: 7u161, 8u152 and 9.0.1; Java SE Embedded: 8u151. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Java SE, Java SE Embedded. 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 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 3.0 Base Score 6.8 (Confidentiality impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N).
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 01/31/2021
The vulnerability identified as CVE-2018-2634 resides within the Java GSS (Generic Security Services) subsystem of Oracle Java SE and Java SE Embedded platforms. This flaw specifically affects versions 7u161, 8u152, and 9.0.1 of Java SE along with 8u151 of Java SE Embedded, representing a significant security weakness that can be exploited by unauthenticated attackers. The vulnerability operates at the network level with a CVSS 3.0 base score of 6.8, indicating a medium to high severity threat that requires network access and has a high attack complexity. The flaw demonstrates characteristics of a remote code execution vulnerability that could potentially compromise the confidentiality of critical data within Java deployments.
The technical implementation of this vulnerability stems from improper validation within the JGSS component that handles security services in Java applications. This weakness allows attackers to manipulate authentication and authorization processes through multiple network protocols, potentially bypassing the sandboxed environment that typically protects Java applications. The vulnerability's exploitation occurs when Java applications running in sandboxed environments load untrusted code from external sources, such as web applications or applets that rely on the Java sandbox for security boundaries. The flaw specifically impacts the Java Web Start applications and Java applets that operate under security constraints, where the JGSS functionality is leveraged for authentication purposes.
The operational impact of CVE-2018-2634 extends beyond the immediate Java environment and can significantly affect additional products that depend on Java SE or Java SE Embedded components. Successful exploitation of this vulnerability can lead to unauthorized access to critical system data and potentially full access to all data accessible through Java SE or Java SE Embedded applications. The vulnerability's classification under CWE-284 (Improper Access Control) and its alignment with ATT&CK technique T1068 (Exploitation for Privilege Escalation) demonstrates how attackers can leverage this weakness to gain unauthorized access to sensitive information. The attack vector specifically targets Java deployments in client environments where untrusted code execution is permitted, making web-based applications particularly vulnerable.
Mitigation strategies for CVE-2018-2634 should prioritize immediate patching of affected Java versions to the latest available updates from Oracle. Organizations must also implement network segmentation and access controls to limit exposure of Java applications to untrusted networks. Security administrators should disable Java in web browsers or configure Java to run in a restricted environment when not absolutely necessary. The vulnerability's characteristics align with ATT&CK technique T1190 (Exploit Public-Facing Application) and require defensive measures such as network monitoring for suspicious authentication attempts and implementing application whitelisting policies. Additionally, organizations should conduct thorough assessments of their Java deployment environments to identify and isolate applications that may be vulnerable to this specific JGSS implementation weakness, particularly focusing on applications that load code from external sources without proper validation mechanisms.