CVE-2009-2832 in Mac OS X
Summary
by MITRE
Buffer overflow in FTP Server in Apple Mac OS X before 10.6.2 allows remote attackers to execute arbitrary code or cause a denial of service (daemon crash) via a CWD command specifying a pathname in a deeply nested hierarchy of directories, related to a "CWD command line tool."
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Analysis
by VulDB Data Team • 06/02/2025
The vulnerability identified as CVE-2009-2832 represents a critical buffer overflow flaw within the FTP server component of Apple Mac OS X operating systems prior to version 10.6.2. This issue specifically affects the CWD (Change Working Directory) command implementation, which serves as a fundamental command for navigating file system structures within FTP sessions. The vulnerability arises from insufficient input validation and boundary checking when processing directory pathnames that exhibit deeply nested hierarchical structures. Attackers can exploit this weakness by crafting malicious CWD commands containing excessively deep directory paths that exceed the allocated buffer space, thereby triggering memory corruption. The technical nature of this flaw aligns with CWE-121, which describes classic buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. This vulnerability operates at the application layer of the network stack, specifically targeting the File Transfer Protocol daemon that runs on Mac OS X systems.
The operational impact of CVE-2009-2832 extends beyond simple denial of service conditions to encompass full remote code execution capabilities. When a maliciously crafted CWD command is processed, the buffer overflow can corrupt critical program memory structures including return addresses, function pointers, and other control data. This memory corruption creates opportunities for attackers to inject and execute arbitrary code within the context of the FTP daemon process, potentially leading to complete system compromise. The daemon crash aspect of the vulnerability demonstrates the immediate availability impact, where legitimate users experience service disruption while attackers can leverage the same mechanism to establish persistent access. This flaw particularly affects systems running Mac OS X versions earlier than 10.6.2, making it a significant concern for organizations maintaining legacy systems. The vulnerability's exploitation requires minimal privileges and can be executed remotely, aligning with ATT&CK technique T1190 for exploiting vulnerabilities in remote services and T1059 for command and scripting interpreters.
Mitigation strategies for CVE-2009-2832 primarily focus on immediate system updates and operational security measures. The most effective remediation involves upgrading affected Mac OS X systems to version 10.6.2 or later, where Apple implemented proper input validation and buffer size limitations for CWD command processing. System administrators should also consider implementing network segmentation and access controls to limit exposure of FTP services to trusted networks only. Additional protective measures include configuring FTP daemon logging to monitor for suspicious CWD command patterns, implementing intrusion detection systems to detect anomalous directory traversal attempts, and conducting regular security assessments of network services. Organizations should also consider disabling FTP services entirely when not required and migrating to more secure protocols such as SFTP or FTPS where available. The vulnerability demonstrates the importance of proper input validation and buffer management in network services, reinforcing industry best practices outlined in security frameworks such as the OWASP Top Ten and NIST cybersecurity guidelines for secure coding practices.