CVE-2009-1094 in JRE
Summary
by MITRE
Unspecified vulnerability in the LDAP implementation in Java SE Development Kit (JDK) and Java Runtime Environment (JRE) 5.0 Update 17 and earlier; 6 Update 12 and earlier; SDK and JRE 1.3.1_24 and earlier; and 1.4.2_19 and earlier allows remote LDAP servers to execute arbitrary code via unknown vectors related to serialized data.
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Analysis
by VulDB Data Team • 08/09/2021
The vulnerability identified as CVE-2009-1094 represents a critical security flaw within the Lightweight Directory Access Protocol implementation of various Java runtime environments. This issue affects multiple versions of the Java Development Kit and Runtime Environment spanning from early versions of Java 1.3.1 through Java 6, with specific affected releases including JDK/JRE 5.0 Update 17 and earlier, 6 Update 12 and earlier, 1.3.1_24 and earlier, and 1.4.2_19 and earlier. The vulnerability stems from insufficient validation mechanisms within the Java serialization framework when processing LDAP data, creating a pathway for remote code execution attacks.
The technical root cause of this vulnerability lies in the improper handling of serialized objects within the LDAP client implementation. When Java applications process LDAP responses containing maliciously crafted serialized data, the deserialization process fails to properly validate the incoming data structure, allowing attackers to inject arbitrary code that executes within the context of the running Java application. This flaw operates at the serialization level where the Java Virtual Machine deserializes objects without adequate safeguards against malicious input, making it particularly dangerous as it can be exploited through network-based LDAP connections without requiring authentication or local access to the target system.
From an operational perspective, this vulnerability presents significant risk to organizations relying on Java applications that interact with LDAP servers, particularly those implementing directory services for authentication, authorization, and user management. Attackers can exploit this weakness by setting up malicious LDAP servers that respond to queries with specially crafted serialized objects designed to trigger code execution upon deserialization. The impact extends beyond simple remote code execution to potentially allow full system compromise, privilege escalation, and unauthorized access to sensitive data stored in directory services. This vulnerability directly aligns with CWE-502 which describes "Deserialization of Untrusted Data" and represents a classic example of how serialization flaws can lead to arbitrary code execution in enterprise applications.
The attack surface for this vulnerability encompasses any Java application that utilizes LDAP for directory services, including enterprise applications, web applications, and middleware components that depend on LDAP for user authentication and authorization. Organizations running affected Java versions are particularly vulnerable when their applications connect to untrusted LDAP servers or when LDAP queries are processed without proper input validation. The remote exploitation capability means that attackers do not need physical access to systems, making this vulnerability particularly attractive for large-scale attacks against enterprise networks. Security frameworks such as the ATT&CK matrix categorize this as a remote code execution technique that can be leveraged for privilege escalation and persistence within targeted environments.
Mitigation strategies for CVE-2009-1094 primarily focus on immediate version upgrades to patched Java releases that address the serialization vulnerability in LDAP implementations. Organizations should prioritize upgrading to Java versions that have been specifically patched to address this issue, typically involving updates to JDK/JRE 5.0 Update 18, 6 Update 13, and later versions. Additional protective measures include implementing network segmentation to limit LDAP connectivity, configuring firewalls to restrict access to LDAP servers, and applying application-level input validation to LDAP responses. Security monitoring should be enhanced to detect unusual LDAP traffic patterns that might indicate exploitation attempts, while organizations should also consider implementing Java security policies that restrict deserialization operations to trusted sources only. The remediation process should include comprehensive testing of applications to ensure that the patches do not introduce compatibility issues while maintaining the security posture against this and similar serialization-based vulnerabilities.