CVE-2007-3876 in Mac OS X
Summary
by MITRE
Stack-based buffer overflow in SMB in Apple Mac OS X 10.4.11 allows local users to execute arbitrary code via (1) a long workgroup (-W) option to mount_smbfs or (2) an unspecified manipulation of the command line to smbutil.
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Analysis
by VulDB Data Team • 06/07/2025
The vulnerability described in CVE-2007-3876 represents a critical stack-based buffer overflow affecting Apple Mac OS X 10.4.11 operating system. This flaw exists within the Server Message Block (SMB) implementation and specifically targets the mount_smbfs utility and smbutil command line tool. The vulnerability stems from inadequate input validation mechanisms that fail to properly bounds-check user-supplied arguments before copying them into fixed-size stack buffers. When local attackers provide excessively long workgroup parameters using the -W option to mount_smbfs, or manipulate command line arguments to smbutil in an unspecified manner, the system experiences buffer overflow conditions that can be exploited to execute arbitrary code with the privileges of the affected process.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations on the stack. The attack vector is particularly concerning because it requires only local user privileges to exploit, making it accessible to users who have already gained access to the system through other means or who have legitimate administrative access. The vulnerability affects the core SMB functionality that enables Mac OS X systems to connect to Windows file shares and other SMB-compatible services, creating potential for privilege escalation attacks that could allow malicious actors to gain elevated system privileges or execute arbitrary code within the context of the affected processes.
From an operational impact perspective, this vulnerability presents significant security risks to Mac OS X 10.4.11 systems, particularly in enterprise environments where SMB connectivity is frequently used for file sharing and network resource access. The local execution requirement means that attackers would need to already have access to the system, but once compromised, they could leverage this vulnerability to escalate privileges or establish persistent access. The attack surface is broad since both mount_smbfs and smbutil utilities are commonly used system tools that may be invoked by various system processes or by users during normal operations. The exploitation could potentially allow attackers to bypass security controls, access sensitive data, or use the compromised system as a launch point for further attacks within the network infrastructure.
Mitigation strategies for this vulnerability should focus on immediate patch application through Apple's security updates, as the vendor would have released a fix addressing the buffer overflow conditions in the SMB implementation. System administrators should also implement monitoring for unusual usage patterns of mount_smbfs and smbutil utilities, particularly when invoked with unusually long parameters or from unexpected contexts. Network segmentation and access controls should be reinforced to limit local user privileges where possible, reducing the potential impact of successful exploitation. Additionally, implementing proper input validation and bounds checking in system utilities represents a fundamental defensive measure that aligns with the principle of least privilege and defense in depth strategies. Organizations should also consider disabling unnecessary SMB functionality when not required for business operations, and maintain regular security assessments to identify similar vulnerabilities in other system components that might be susceptible to similar buffer overflow exploitation techniques. The vulnerability demonstrates the importance of maintaining up-to-date system patches and the critical nature of proper input validation in preventing exploitation of memory corruption vulnerabilities that could lead to complete system compromise.