CVE-2018-14879 in tcpdump
Summary
by MITRE
The command-line argument parser in tcpdump before 4.9.3 has a buffer overflow in tcpdump.c:get_next_file().
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Analysis
by VulDB Data Team • 12/03/2025
The vulnerability identified as CVE-2018-14879 represents a critical buffer overflow flaw within the tcpdump network analysis tool's command-line argument parsing functionality. This issue specifically manifests in the tcpdump.c:get_next_file() function, which is responsible for handling file name arguments when processing network traffic captures. The buffer overflow occurs when tcpdump processes command-line arguments that contain excessively long file names or path specifications, creating a potential avenue for arbitrary code execution. The vulnerability affects all versions of tcpdump prior to 4.9.3, making it a significant concern for network security professionals who rely on this widely-used packet capture utility. The flaw stems from inadequate input validation and bounds checking within the argument parsing logic, allowing attackers to overflow a fixed-size buffer and potentially overwrite adjacent memory locations.
The technical exploitation of this vulnerability requires an attacker to craft a malicious command-line argument containing an overly long string that exceeds the allocated buffer space in the get_next_file() function. This buffer overflow can be leveraged to execute arbitrary code with the privileges of the user running tcpdump, potentially leading to complete system compromise. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of improper input validation in network security tools. When tcpdump processes a command-line argument that triggers this overflow, the program's execution flow can be redirected through memory corruption, enabling attackers to inject and execute malicious code. The attack surface is particularly concerning because tcpdump is frequently used in security monitoring, incident response, and network troubleshooting scenarios where it may be executed with elevated privileges.
The operational impact of CVE-2018-14879 extends beyond simple denial of service to encompass full system compromise and data exfiltration capabilities. In environments where tcpdump is used with root privileges or in automated security workflows, an attacker could exploit this vulnerability to gain unauthorized access to network monitoring systems. The vulnerability affects both local and remote attack scenarios, as attackers could potentially manipulate command-line arguments through various attack vectors including compromised network monitoring infrastructure or misconfigured automated systems. Organizations using tcpdump for network security operations face significant risk, as the tool's widespread deployment across enterprise networks means that exploitation could affect multiple systems simultaneously. The vulnerability also impacts security tools that depend on tcpdump for packet analysis, creating cascading effects throughout network security infrastructure.
Mitigation strategies for CVE-2018-14879 center on immediate patching of tcpdump to version 4.9.3 or later, which contains the necessary buffer overflow protections and input validation fixes. System administrators should conduct comprehensive inventory checks to identify all systems running vulnerable versions of tcpdump and prioritize remediation efforts accordingly. Additional protective measures include implementing strict input validation for command-line arguments, using privilege separation techniques to limit tcpdump execution privileges, and monitoring for suspicious command-line usage patterns. The vulnerability demonstrates the importance of input validation in security tools, aligning with ATT&CK technique T1059.001 for command and scripting interpreter usage, where attackers may exploit such vulnerabilities to execute malicious commands through manipulated arguments. Organizations should also consider implementing network segmentation and access controls to limit exposure, while maintaining regular security updates to prevent similar vulnerabilities from being introduced through third-party tools. The incident underscores the necessity of robust software security practices and continuous vulnerability assessment in network security tooling.