CVE-2004-0368 in AIX
Summary
by MITRE
Double free vulnerability in dtlogin in CDE on Solaris, HP-UX, and other operating systems allows remote attackers to execute arbitrary code via a crafted XDMCP packet.
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Analysis
by VulDB Data Team • 07/13/2025
The vulnerability identified as CVE-2004-0368 represents a critical double free condition within the dtlogin component of the Common Desktop Environment (CDE) across multiple Unix operating systems including Solaris and HP-UX. This flaw exists in the X Display Manager Control Protocol (XDMCP) implementation where the dtlogin service processes incoming packets from remote clients. The double free vulnerability occurs when the application improperly handles memory allocation and deallocation sequences, leading to a situation where the same memory block is freed twice during the processing of a maliciously crafted XDMCP packet. Such memory corruption creates exploitable conditions that can be leveraged by remote attackers to gain unauthorized code execution privileges on affected systems. The vulnerability is particularly concerning because it operates at the graphical login level, providing attackers with potential access to systems during the authentication phase when users are attempting to establish desktop sessions.
The technical implementation of this vulnerability stems from improper memory management within the dtlogin service's XDMCP packet handling routines. When processing a specially crafted XDMCP packet, the application allocates memory for various data structures including display name and authentication information. Under normal circumstances, the application would properly manage these allocations and deallocations. However, the double free condition arises when the application's packet parsing logic fails to properly validate or process certain packet fields, causing the same memory chunk to be deallocated twice. This memory corruption can be exploited to overwrite critical program data structures or function pointers, allowing an attacker to redirect execution flow. The vulnerability is classified as a CWE-415 Double Free, which is a well-documented weakness in memory management where a pointer is freed twice, potentially leading to arbitrary code execution. The ATT&CK framework categorizes this as a memory corruption technique that can be used for privilege escalation and code execution.
The operational impact of CVE-2004-0368 extends beyond simple remote code execution, as it provides attackers with a pathway to compromise entire desktop environments and potentially gain access to sensitive user data. Since dtlogin serves as the primary graphical login interface for CDE, exploitation can occur during normal user authentication attempts, making it particularly dangerous in environments where users frequently connect to systems remotely. The vulnerability affects systems running CDE versions prior to the security patches, with specific versions including CDE 1.0 through 1.5 on Solaris and equivalent versions on HP-UX. Attackers can leverage this vulnerability to execute arbitrary commands with the privileges of the dtlogin process, which typically runs with elevated permissions to manage user sessions and authentication. The attack requires no authentication from the attacker, as the vulnerability can be exploited through unauthenticated XDMCP packets sent over the network, making it particularly attractive to threat actors seeking to compromise systems without prior access credentials. Additionally, the nature of the vulnerability means that exploitation can be automated, potentially allowing for large-scale attacks against multiple systems simultaneously.
Mitigation strategies for CVE-2004-0368 primarily focus on immediate patching and network-level controls to prevent exploitation. System administrators should prioritize applying vendor security patches that address the memory management issues in dtlogin, particularly those released by Sun Microsystems for Solaris and Hewlett-Packard for HP-UX systems. The most effective immediate mitigation involves disabling XDMCP services entirely, as this prevents the vulnerable packet processing from occurring. Network segmentation and firewall rules should be implemented to block XDMCP traffic (UDP port 177) from reaching affected systems where possible. Additionally, monitoring for unusual XDMCP traffic patterns and implementing intrusion detection systems can help identify potential exploitation attempts. Organizations should also consider disabling the CDE desktop environment entirely if it is not essential for operations, as this removes the attack surface entirely. The vulnerability serves as a reminder of the importance of proper memory management in security-critical applications and highlights the need for regular security assessments of desktop environments and authentication services. For systems that cannot be immediately patched, implementing network-based controls to prevent XDMCP access from untrusted networks provides a temporary but effective defense against this specific exploit vector.