CVE-2009-2727 in AIX
Summary
by MITRE
Stack-based buffer overflow in the _tt_internal_realpath function in the ToolTalk library (libtt.a) in IBM AIX 5.2.0, 5.3.0, 5.3.7 through 5.3.10, and 6.1.0 through 6.1.3, when the rpc.ttdbserver daemon is enabled in /etc/inetd.conf, allows remote attackers to execute arbitrary code via a long XDR-encoded ASCII string to remote procedure 15.
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Analysis
by VulDB Data Team • 03/30/2025
The vulnerability identified as CVE-2009-2727 represents a critical stack-based buffer overflow within the ToolTalk library component of IBM AIX operating systems. This flaw exists in the _tt_internal_realpath function, which is part of libtt.a, a core library responsible for ToolTalk services that facilitate inter-process communication between applications. The vulnerability specifically affects IBM AIX versions 5.2.0, 5.3.0, and multiple subsequent patch levels including 5.3.7 through 5.3.10, as well as 6.1.0 through 6.1.3. The exploitation occurs through the rpc.ttdbserver daemon, which must be enabled in the /etc/inetd.conf configuration file for the attack to be successful, making this vulnerability particularly concerning for systems that have ToolTalk services actively running.
The technical implementation of this vulnerability stems from inadequate input validation within the _tt_internal_realpath function. When the rpc.ttdbserver daemon processes remote procedure calls, it accepts XDR-encoded ASCII strings as part of the communication protocol. The function fails to properly bounds-check the length of these input strings before copying them into a fixed-size stack buffer, creating a classic stack-based buffer overflow condition. This allows an attacker to overwrite adjacent stack memory locations including return addresses and function pointers, potentially enabling arbitrary code execution with the privileges of the rpc.ttdbserver daemon process. The vulnerability is specifically triggered through remote procedure 15, which suggests this is a well-defined interface within the ToolTalk RPC framework that handles path resolution operations.
The operational impact of this vulnerability extends beyond simple code execution, as it represents a significant escalation path for attackers targeting IBM AIX systems. Since the rpc.ttdbserver daemon typically runs with elevated privileges, successful exploitation could allow remote attackers to gain unauthorized access to system resources, potentially leading to complete system compromise. The vulnerability's remote nature means that attackers do not require local access to exploit it, making it particularly dangerous in networked environments where AIX systems may be exposed to external networks. The specific version targeting indicates that this was a long-standing issue that affected multiple generations of IBM AIX releases, suggesting that organizations running these systems were potentially exposed for extended periods without proper patching. This vulnerability aligns with CWE-121, stack-based buffer overflow, and represents a typical attack vector that would be catalogued under the ATT&CK technique T1059 for execution through remote services.
Mitigation strategies for CVE-2009-2727 should focus on immediate patch application from IBM, as the vendor would have released specific security fixes for the affected AIX versions. Organizations should also consider disabling the rpc.ttdbserver daemon if ToolTalk services are not actively required, effectively removing the attack surface through configuration changes. Network segmentation and firewall rules should be implemented to restrict access to the affected daemon's ports, particularly when the service must remain enabled for operational purposes. Additionally, monitoring for suspicious XDR traffic patterns and implementing intrusion detection systems that can identify attempts to exploit buffer overflow conditions would provide defense-in-depth measures. The vulnerability demonstrates the importance of proper input validation in RPC frameworks and highlights the need for regular security assessments of system components that handle remote procedure calls, particularly those that operate with elevated privileges. Organizations should also review their patch management processes to ensure timely application of security updates, as this vulnerability likely remained unpatched for extended periods in many production environments.