CVE-2016-7923 in macOS
Summary
by MITRE
The ARP parser in tcpdump before 4.9.0 has a buffer overflow in print-arp.c:arp_print().
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Analysis
by VulDB Data Team • 05/16/2026
The vulnerability identified as CVE-2016-7923 represents a critical buffer overflow flaw within the tcpdump network analysis tool that affects versions prior to 4.9.0. This issue specifically resides in the Address Resolution Protocol (ARP) parser component, which is responsible for interpreting and displaying ARP packets captured during network monitoring operations. The buffer overflow occurs within the print-arp.c source file at the arp_print() function, making it a direct consequence of improper input validation and memory management practices. The vulnerability manifests when tcpdump processes malformed or specially crafted ARP packets that exceed the allocated buffer space, potentially leading to arbitrary code execution or system instability.
The technical implementation of this flaw stems from insufficient bounds checking within the arp_print() function, which fails to properly validate the length of incoming ARP packet data before attempting to copy it into fixed-size buffers. This classic buffer overflow vulnerability falls under CWE-121, which categorizes buffer overflow conditions where insufficient validation allows attackers to overwrite adjacent memory locations. The vulnerability is particularly concerning because tcpdump is widely deployed across enterprise networks for network monitoring, security auditing, and forensic analysis purposes, making it a prime target for exploitation. When an attacker crafts malicious ARP packets that trigger this buffer overflow, the consequences can range from denial of service conditions that disrupt network monitoring operations to more severe scenarios where remote code execution becomes possible through carefully constructed input data that overflows the stack.
The operational impact of CVE-2016-7923 extends beyond simple system crashes or service disruptions, as it represents a significant threat to network security infrastructure. Network administrators who rely on tcpdump for intrusion detection, packet analysis, and security monitoring may find their tools compromised when processing malicious traffic. The vulnerability aligns with ATT&CK technique T1046, which describes network service scanning, as attackers could exploit this flaw to gain unauthorized access to systems running vulnerable tcpdump versions. Additionally, the flaw intersects with T1059, representing the execution of commands through network monitoring tools, as compromised tcpdump instances could be used to execute malicious payloads. Organizations using tcpdump in production environments face potential data exposure risks, as attackers who successfully exploit this vulnerability could gain access to sensitive network information, disrupt network operations, or establish persistent access points within their network infrastructure.
Mitigation strategies for CVE-2016-7923 primarily focus on immediate version upgrades to tcpdump 4.9.0 or later, which contain fixed implementations of the arp_print() function with proper bounds checking. System administrators should prioritize patching affected systems and verify that all network monitoring infrastructure is updated to prevent exploitation. Additional defensive measures include implementing network segmentation to limit exposure, deploying intrusion detection systems that can identify and block malicious ARP traffic patterns, and configuring tcpdump to run with restricted privileges to minimize potential impact if exploitation occurs. The vulnerability also underscores the importance of regular security audits and vulnerability assessments of network monitoring tools, as similar issues may exist in other components of tcpdump or related network analysis software. Organizations should consider implementing network traffic filtering rules that can detect and prevent malformed ARP packets from reaching tcpdump processes, providing an additional layer of defense against this type of exploitation.