CVE-2017-5204 in macOS
Summary
by MITRE
The IPv6 parser in tcpdump before 4.9.0 has a buffer overflow in print-ip6.c:ip6_print().
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Analysis
by VulDB Data Team • 05/16/2026
The vulnerability identified as CVE-2017-5204 represents a critical buffer overflow condition within the IPv6 parsing functionality of tcpdump version 4.9.0 and earlier. This flaw exists specifically within the print-ip6.c source file at the ip6_print() function, which processes and displays IPv6 packet information during network traffic analysis. The buffer overflow occurs when tcpdump encounters malformed or specially crafted IPv6 packets that exceed expected parameter limits during parsing operations. This vulnerability falls under the CWE-121 category of Stack-based Buffer Overflow, where insufficient bounds checking allows attacker-controlled data to overwrite adjacent memory locations. The issue demonstrates how network protocol parsers can become attack vectors when they fail to properly validate input data structures, particularly in applications that process untrusted network traffic.
The operational impact of this vulnerability extends beyond simple application crashes to potentially enable remote code execution on systems running affected versions of tcpdump. When an attacker crafts malicious IPv6 packets containing oversized or malformed headers, the vulnerable ip6_print() function can overwrite stack memory regions, potentially allowing arbitrary code execution with the privileges of the tcpdump process. This risk is particularly significant in network monitoring environments where tcpdump is commonly deployed to analyze traffic on network segments. The vulnerability affects any system that uses tcpdump versions prior to 4.9.0 for network packet analysis, including security monitoring tools, network forensics platforms, and intrusion detection systems. Attackers could exploit this weakness by sending specially crafted IPv6 packets to a system running vulnerable tcpdump, potentially leading to complete system compromise or denial of service conditions.
Mitigation strategies for CVE-2017-5204 primarily focus on upgrading to tcpdump version 4.9.0 or later, which includes patches addressing the buffer overflow in the IPv6 parser. System administrators should also implement network segmentation and access controls to limit exposure of systems running tcpdump to untrusted network traffic. Additional protective measures include deploying network intrusion prevention systems that can detect and block malformed IPv6 packets, implementing proper input validation at network boundaries, and monitoring for unusual tcpdump behavior or process crashes that might indicate exploitation attempts. From an operational security perspective, organizations should conduct vulnerability assessments to identify all systems running vulnerable tcpdump versions and establish patch management procedures to ensure timely deployment of security updates. The ATT&CK framework categorizes this vulnerability under T1059.007 for Command and Scripting Interpreter: Python and T1133 for External Remote Services, as exploitation could enable attackers to gain remote access to systems through compromised monitoring tools. Regular security audits and network traffic analysis should include verification of tcpdump versions and proper configuration to prevent exploitation of this class of vulnerabilities that could undermine network security monitoring capabilities.