CVE-2016-7926 in macOS
Summary
by MITRE
The Ethernet parser in tcpdump before 4.9.0 has a buffer overflow in print-ether.c:ethertype_print().
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Analysis
by VulDB Data Team • 05/16/2026
The vulnerability identified as CVE-2016-7926 represents a critical buffer overflow condition within the tcpdump network packet analysis tool, specifically affecting versions prior to 4.9.0. This issue resides in the Ethernet parser component of tcpdump, which is widely utilized by network security professionals, system administrators, and forensic analysts for capturing and analyzing network traffic. The vulnerability manifests in the print-ether.c source file at the ethertype_print() function, where insufficient input validation allows maliciously crafted network packets to trigger memory corruption. The buffer overflow occurs when tcpdump processes Ethernet frames containing specially constructed data that exceeds the allocated buffer space, potentially leading to arbitrary code execution or application crash.
The technical flaw stems from inadequate bounds checking within the Ethernet protocol parsing logic, where the ethertype_print() function fails to properly validate the length of incoming Ethernet frame data before attempting to process it. This vulnerability directly maps to CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which addresses heap-based buffer overflow scenarios. The flaw allows an attacker to craft malicious network packets that, when processed by the vulnerable tcpdump version, can overwrite adjacent memory locations. This memory corruption can result in unpredictable behavior including application termination, denial of service, or in more severe cases, remote code execution depending on the system's memory layout and security mitigations in place. The vulnerability is particularly concerning because tcpdump is often run with elevated privileges in network monitoring scenarios, amplifying the potential impact of exploitation.
The operational impact of this vulnerability extends across numerous network security environments where tcpdump serves as a fundamental tool for network analysis and troubleshooting. Security professionals and network administrators who rely on tcpdump for packet capture and analysis may find their systems compromised if they process malicious network traffic without proper version updates. The vulnerability affects not only standalone systems but also network monitoring appliances, intrusion detection systems, and security information and event management platforms that utilize tcpdump as a core component. In enterprise environments, this could lead to unauthorized access to network monitoring capabilities, disruption of security operations, and potential data exfiltration through command execution. The vulnerability also impacts automated network scanning and monitoring tools that depend on tcpdump for network traffic analysis, creating cascading effects throughout network security infrastructure.
Mitigation strategies for CVE-2016-7926 primarily focus on immediate software updates to tcpdump version 4.9.0 or later, which contain the necessary patches to address the buffer overflow condition. System administrators should conduct comprehensive vulnerability assessments to identify all systems running vulnerable versions of tcpdump and prioritize patch deployment across network monitoring infrastructure. Additional defensive measures include implementing network segmentation to limit exposure to potentially malicious traffic, deploying network access controls to restrict packet capture operations, and ensuring tcpdump is executed with minimal privileges when possible. Organizations should also consider implementing network anomaly detection systems to identify unusual packet patterns that may indicate exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date network security tools and demonstrates how seemingly benign network analysis utilities can become attack vectors when vulnerable to buffer overflow conditions. Security teams should integrate tcpdump version verification into their regular compliance and vulnerability management processes to prevent similar issues from affecting their network monitoring capabilities.