CVE-2009-0609 in Java System Directory Server
Summary
by MITRE
Sun Java System Directory Proxy Server in Sun Java System Directory Server Enterprise Edition 6.0 through 6.3, when a JDBC data source is used, does not properly handle (1) a long value in an ADD or (2) long string attributes, which allows remote attackers to cause a denial of service (JDBC backend outage) via crafted LDAP requests.
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Analysis
by VulDB Data Team • 08/04/2021
The vulnerability identified as CVE-2009-0609 affects Sun Java System Directory Proxy Server within the Sun Java System Directory Server Enterprise Edition versions 6.0 through 6.3. This issue manifests when the system utilizes JDBC data sources for backend storage, creating a specific weakness in how the server processes certain LDAP operations. The vulnerability resides in the server's inability to properly manage extended data values during directory operations, specifically when handling ADD operations and long string attributes. This flaw represents a critical security concern as it can be exploited by remote attackers to disrupt service availability through targeted LDAP requests.
The technical implementation of this vulnerability stems from inadequate input validation and handling within the JDBC backend integration layer of the directory proxy server. When an attacker crafts malicious LDAP requests containing exceptionally long values or attributes, the server fails to process these inputs appropriately, leading to system instability and potential backend database connection failures. The flaw operates at the protocol level where LDAP ADD operations and attribute handling do not properly validate or limit the size of data being processed, causing the JDBC connection to become unresponsive or crash entirely. This behavior aligns with CWE-129, which addresses improper validation of length of input buffers, and demonstrates how inadequate bounds checking can lead to denial of service conditions.
From an operational impact perspective, this vulnerability creates significant risk for organizations relying on the affected directory server versions for authentication, authorization, and directory services. A successful exploitation can result in complete service disruption of the directory proxy server, effectively cutting off access to directory services for all dependent applications and users. The denial of service condition specifically targets the JDBC backend connections, which can cascade to affect the entire directory infrastructure and potentially compromise business continuity. Attackers can leverage this vulnerability without requiring authentication credentials, making it particularly dangerous as it allows for easy exploitation by any remote party with network access to the directory server. The impact extends beyond simple service interruption to include potential data integrity concerns and system recovery complications.
Organizations should implement immediate mitigations including applying the vendor-provided patches and updates released to address this vulnerability. Network segmentation and access control measures can help limit exposure by restricting direct network access to the directory server from untrusted networks. Implementing monitoring solutions to detect unusual LDAP traffic patterns and large attribute values can provide early warning of potential exploitation attempts. Additionally, configuring input validation rules and implementing proper data size limits for LDAP operations can help prevent exploitation. The remediation approach should align with ATT&CK technique T1499.004, which focuses on network denial of service attacks, by ensuring proper input handling and resource management to prevent the exploitation of buffer overflow conditions. Organizations should also consider implementing redundant directory services and backup authentication mechanisms to maintain operational continuity during vulnerability remediation periods.