CVE-2018-2657 in Java SE
Summary
by MITRE
Vulnerability in the Java SE, JRockit component of Oracle Java SE (subcomponent: Serialization). Supported versions that are affected are Java SE: 6u171 and 7u161; JRockit: R28.3.16. Easily exploitable vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Java SE, JRockit. Successful attacks of this vulnerability can result in unauthorized ability to cause a partial denial of service (partial DOS) of Java SE, JRockit. Note: This vulnerability can only be exploited by supplying data to APIs in the specified Component without using Untrusted Java Web Start applications or Untrusted Java applets, such as through a web service. CVSS 3.0 Base Score 5.3 (Availability impacts). CVSS Vector: (CVSS:3.0/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 • 01/31/2021
The vulnerability described in CVE-2018-2657 represents a critical flaw within the serialization component of Oracle Java SE and JRockit runtime environments. This weakness specifically targets the Java serialization mechanism that handles object deserialization processes, which are fundamental to Java application functionality. The vulnerability affects Java SE versions 6u171 and 7u161 along with JRockit version R28.3.16, making it particularly concerning given the widespread deployment of these runtime environments across enterprise systems. The affected serialization subsystem operates as a core component within the Java platform, processing data streams that applications receive from external sources, including network communications and file inputs.
The technical nature of this vulnerability stems from insufficient validation of serialized data during the deserialization process, creating opportunities for attackers to craft malicious input streams that can trigger unintended behavior within the Java runtime. This flaw operates at the binary protocol level where serialized objects are reconstructed from byte streams, allowing an attacker to manipulate the deserialization logic through carefully crafted payloads. The vulnerability's classification as easily exploitable indicates that minimal technical expertise is required to develop working attack vectors, while the network accessibility requirement means that attackers can leverage standard network protocols to deliver malicious payloads without authentication. The CVSS score of 5.3 reflects the availability impact, specifically indicating partial denial of service conditions that can disrupt application functionality and system operations.
From an operational standpoint, the attack scenario involves an unauthenticated network-based attacker who can supply malicious data directly to the affected APIs without relying on traditional web applet or Java Web Start mechanisms. This restriction actually makes the vulnerability more dangerous as it eliminates the need for social engineering or browser-based exploitation techniques, allowing direct system compromise through web service interfaces or other API endpoints. The partial denial of service impact means that while complete system compromise may not occur, the vulnerability can effectively disrupt service availability and potentially allow further exploitation opportunities. Organizations using affected Java versions face significant risk as this vulnerability can be leveraged to degrade system performance, cause application crashes, or create conditions that facilitate additional attacks within the network environment.
The security implications extend beyond simple availability impacts to encompass potential exploitation pathways that align with ATT&CK framework techniques for execution and privilege escalation. This vulnerability demonstrates the dangers of insufficient input validation in core platform components, a weakness that maps directly to CWE-502 (Deserialization of Untrusted Data) which is a common vector for remote code execution and system compromise attacks. Organizations should implement immediate mitigations including patching to the latest Java versions, network segmentation to limit exposure, and monitoring for unusual deserialization patterns. Additionally, security teams should consider implementing application firewalls and input validation controls specifically targeting serialization protocols to reduce the attack surface. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date Java runtime environments and implementing defense-in-depth strategies that protect against exploitation of core platform components.