CVE-2016-7937 in macOS
Summary
by MITRE
The VAT parser in tcpdump before 4.9.0 has a buffer overflow in print-udp.c:vat_print().
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Analysis
by VulDB Data Team • 05/16/2026
The vulnerability identified as CVE-2016-7937 represents a critical buffer overflow flaw within the tcpdump network packet analysis tool. This issue specifically affects versions prior to 4.9.0 and resides within the VAT (VAT Protocol) parser implementation. The vulnerability manifests in the print-udp.c source file at the vat_print() function, where insufficient input validation and bounds checking allow maliciously crafted network packets to trigger memory corruption. The VAT protocol is commonly used for network monitoring and analysis, making this vulnerability particularly dangerous in environments where tcpdump is deployed for security monitoring and network traffic inspection.
The technical nature of this buffer overflow stems from improper handling of variable-length data structures within the VAT protocol parsing logic. When tcpdump processes network packets containing VAT protocol data, the vat_print() function fails to properly validate the length of incoming data before copying it into fixed-size buffers. This allows an attacker to craft packets with oversized VAT protocol headers or data sections that exceed the allocated buffer space, resulting in memory corruption that can overwrite adjacent memory locations. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, where the attacker can manipulate the program execution flow through controlled memory corruption. This type of vulnerability falls within the ATT&CK technique T1059.007 for Command and Scripting Interpreter, as exploitation could lead to arbitrary code execution on systems running vulnerable tcpdump versions.
The operational impact of this vulnerability extends across various network monitoring and security infrastructure components that rely on tcpdump for packet analysis. Systems using tcpdump for intrusion detection, network forensics, or security auditing become susceptible to remote exploitation when processing malicious network traffic. An attacker could potentially leverage this vulnerability to execute arbitrary code with the privileges of the tcpdump process, which typically runs with elevated permissions to capture network packets. The vulnerability is particularly concerning in enterprise environments where tcpdump is used for continuous network monitoring, as a single malicious packet could compromise the entire monitoring infrastructure. Network security tools and firewalls that depend on tcpdump for packet inspection would be vulnerable, potentially allowing attackers to gain unauthorized access to network monitoring capabilities.
Mitigation strategies for CVE-2016-7937 primarily focus on immediate version upgrades to tcpdump 4.9.0 or later, which contain the necessary patches to address the buffer overflow condition. Organizations should implement comprehensive network monitoring to detect and block malicious traffic patterns that could exploit this vulnerability during the transition period. The fix typically involves implementing proper bounds checking and input validation within the vat_print() function to ensure that incoming VAT protocol data does not exceed allocated buffer sizes. Security teams should also consider implementing network segmentation and access controls to limit the exposure of systems running tcpdump to potentially malicious network traffic. Additionally, deploying intrusion prevention systems with signature-based detection for known malicious packet patterns can provide additional layers of protection while awaiting full patch deployment. Regular security audits and vulnerability assessments should be conducted to identify other potential buffer overflow vulnerabilities in network monitoring tools and ensure comprehensive protection against similar threats.