CVE-2015-3773 in Mac OS X
Summary
by MITRE
The SMB client in Apple OS X before 10.10.5 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via unspecified vectors.
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Analysis
by VulDB Data Team • 02/02/2025
The vulnerability identified as CVE-2015-3773 represents a critical security flaw in Apple's SMB client implementation within macOS versions prior to 10.10.5. This vulnerability exposes systems to remote code execution and denial of service attacks through unspecified attack vectors that leverage memory corruption issues within the SMB protocol handling mechanisms. The flaw specifically affects the client-side SMB implementation that is integral to macOS file sharing and network communication capabilities.
The technical nature of this vulnerability stems from improper handling of SMB protocol messages within the operating system's client stack. When processing maliciously crafted SMB responses or requests, the system's memory management routines fail to properly validate input data, leading to memory corruption that can be exploited by remote attackers. This type of vulnerability falls under the CWE-125 weakness category, which describes out-of-bounds read conditions where an attacker can access memory locations beyond the intended buffer boundaries. The memory corruption typically manifests as stack or heap corruption that can be leveraged to execute arbitrary code with the privileges of the affected process, often resulting in system compromise.
From an operational perspective, this vulnerability poses significant risks to enterprise environments where macOS systems may be connected to untrusted networks or interact with malicious SMB servers. Attackers can exploit this weakness to gain unauthorized code execution on target systems, potentially leading to complete system compromise, data exfiltration, or establishment of persistent backdoors. The denial of service aspect further compounds the risk by allowing attackers to cause application crashes and system instability, disrupting normal business operations. The vulnerability's remote exploitability means that attackers do not need physical access to the target system, making it particularly dangerous in networked environments where macOS systems may be exposed to external threats.
Organizations affected by this vulnerability should prioritize immediate patching of all macOS systems to version 10.10.5 or later, which includes the necessary fixes for the SMB client memory handling issues. Network administrators should implement monitoring for suspicious SMB traffic patterns and consider restricting SMB protocol access from untrusted networks where possible. The ATT&CK framework categorizes this type of vulnerability under the T1059.007 technique for Windows command and scripting interpreter, though the specific exploitation vectors may vary based on the target environment and attack surface. System hardening measures should include disabling unnecessary SMB services, implementing network segmentation, and deploying intrusion detection systems to monitor for exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify any remaining unpatched systems within the organization's infrastructure.