CVE-2017-13007 in macOS
Summary
by MITRE
The Apple PKTAP parser in tcpdump before 4.9.2 has a buffer over-read in print-pktap.c:pktap_if_print().
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Analysis
by VulDB Data Team • 09/07/2024
The vulnerability identified as CVE-2017-13007 represents a critical buffer over-read flaw in the Apple PKTAP packet capture parser component of tcpdump versions prior to 4.9.2. This issue specifically affects the print-pktap.c file within the tcpdump utility, where the pktap_if_print() function fails to properly validate input data length before processing Apple PKTAP protocol packets. The flaw occurs during the parsing of network traffic captured in Apple PKTAP format, which is commonly used for wireless network analysis and debugging on macOS systems. When tcpdump encounters malformed or specially crafted PKTAP packets, the parser attempts to read beyond the allocated buffer boundaries, potentially leading to unpredictable behavior and system instability.
The technical implementation of this vulnerability stems from insufficient bounds checking within the packet parsing logic. The pktap_if_print() function processes Apple PKTAP headers and associated data without adequate validation of the packet structure, particularly concerning the length fields that indicate the size of subsequent data segments. This allows an attacker to craft malicious packets that contain oversized or malformed length indicators, causing the parser to access memory locations beyond the intended buffer limits. The vulnerability manifests as a classic buffer over-read condition that can result in information disclosure, application crashes, or potentially arbitrary code execution depending on the system configuration and memory layout. The flaw is categorized under CWE-125 as an out-of-bounds read, which represents a fundamental memory safety issue that can be exploited by remote attackers to compromise system integrity.
From an operational perspective, this vulnerability poses significant risks to network monitoring and security analysis environments that rely on tcpdump for packet capture and inspection. The attack surface is particularly concerning in enterprise networks where wireless traffic analysis is common, as well as in security research and penetration testing scenarios involving macOS systems. The vulnerability can be exploited by remote attackers who have the ability to inject or manipulate network traffic, potentially leading to denial of service conditions, information leakage, or privilege escalation in certain configurations. The impact extends beyond simple service disruption as the over-read could expose sensitive memory contents to unauthorized parties, compromising the confidentiality of network traffic analysis. Security professionals should note that this vulnerability aligns with ATT&CK technique T1046 for network service scanning and T1059 for command and scripting interpreter, as it affects the integrity of network monitoring tools that are critical for defensive operations.
The recommended mitigations for CVE-2017-13007 involve immediate upgrading to tcpdump version 4.9.2 or later, which contains the necessary patches to address the buffer over-read condition. System administrators should also implement network segmentation and access controls to limit exposure to potentially malicious traffic, particularly in environments where wireless network analysis is performed. Additional protective measures include deploying intrusion detection systems that can identify and block malformed PKTAP packets, implementing network monitoring to detect unusual traffic patterns, and conducting regular security assessments of network analysis tools. Organizations should also consider disabling unnecessary packet capture functionality on systems where it is not required for legitimate operational purposes. The fix implemented in tcpdump 4.9.2 involves strengthening input validation in the packet parsing routines, ensuring that all length fields are properly checked against available buffer space before any data is read, thereby preventing the over-read condition that enabled exploitation of this vulnerability.