CVE-2016-7974 in macOS
Summary
by MITRE
The IP parser in tcpdump before 4.9.0 has a buffer overflow in print-ip.c, multiple functions.
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Analysis
by VulDB Data Team • 05/16/2026
The vulnerability identified as CVE-2016-7974 represents a critical buffer overflow flaw within the tcpdump network packet analysis tool, specifically affecting versions prior to 4.9.0. This issue resides in the IP parser component of tcpdump, which is responsible for dissecting and displaying Internet Protocol packets captured from network traffic. The buffer overflow occurs within the print-ip.c source file and affects multiple functions that handle IP packet processing, making it particularly dangerous as it can be triggered through various packet parsing scenarios. The vulnerability stems from insufficient input validation and bounds checking when processing IP headers, allowing maliciously crafted packets to overwrite adjacent memory locations in the application's memory space.
The technical implementation of this buffer overflow vulnerability demonstrates a classic weakness in network protocol parsing where the application fails to properly validate the length and structure of incoming IP packet headers before processing them. When tcpdump encounters an IP packet with malformed or oversized header fields, the parsing functions in print-ip.c do not adequately check buffer boundaries before copying data into internal storage buffers. This lack of proper bounds checking creates an exploitable condition where an attacker can craft packets with maliciously constructed IP headers that cause the application to write beyond allocated memory regions. The vulnerability is particularly concerning because tcpdump is widely used for network monitoring, security auditing, and forensic analysis, making it a common target for exploitation in network-based attacks.
The operational impact of CVE-2016-7974 extends beyond simple application crashes, potentially enabling remote code execution in scenarios where tcpdump is executed with elevated privileges or in environments where attackers can inject malicious network traffic. When exploited successfully, the buffer overflow can lead to denial of service conditions that disrupt network monitoring capabilities, or more severely, allow attackers to execute arbitrary code on systems running vulnerable versions of tcpdump. This vulnerability affects network security professionals and organizations that rely on tcpdump for traffic analysis, as an attacker could potentially compromise monitoring systems during network investigations or security assessments. The flaw particularly impacts environments where tcpdump is used in automated monitoring systems or security appliances, where the application might be processing untrusted network traffic without proper sanitization.
Mitigation strategies for CVE-2016-7974 center on immediate software updates to versions 4.9.0 or later where the buffer overflow has been addressed through proper bounds checking and input validation. System administrators should prioritize patching all instances of tcpdump across network monitoring infrastructure, security appliances, and forensic analysis systems. Additionally, network segmentation and traffic filtering can provide temporary protection by limiting exposure to potentially malicious packets, though this approach does not eliminate the underlying vulnerability. The fix implemented by the tcpdump development team typically involves adding comprehensive input validation checks before buffer operations, ensuring that IP header lengths and field values are properly verified against expected ranges. This vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and represents a common attack vector that could be mapped to ATT&CK technique T1059 for command and control communications or T1046 for network service scanning, depending on the exploitation context and target environment.