CVE-2017-5342 in macOS
Summary
by MITRE
In tcpdump before 4.9.0, a bug in multiple protocol parsers (Geneve, GRE, NSH, OTV, VXLAN and VXLAN GPE) could cause a buffer overflow in print-ether.c:ether_print().
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Analysis
by VulDB Data Team • 05/16/2026
The vulnerability identified as CVE-2017-5342 represents a critical buffer overflow condition affecting tcpdump versions prior to 4.9.0, specifically within the packet parsing functionality of several network protocols including Geneve, GRE, NSH, OTV, VXLAN, and VXLAN GPE. This flaw exists in the print-ether.c module where the ether_print() function processes ethernet frames, creating a scenario where malformed or specially crafted packets can trigger unauthorized memory access patterns. The issue stems from inadequate input validation and bounds checking during protocol parsing operations, allowing attackers to manipulate packet structures that tcpdump encounters during network traffic analysis.
The technical implementation of this vulnerability involves the improper handling of variable-length protocol headers within the tcpdump packet dissection engine. When tcpdump processes packets containing these specific protocols, the parser fails to properly validate the length of incoming data structures before attempting to copy or process the information into fixed-size buffers. This creates an exploitable condition where an attacker can craft packets with oversized or malformed protocol headers that exceed the allocated buffer space, resulting in memory corruption that can potentially lead to arbitrary code execution or application crash. The vulnerability manifests specifically in the context of network traffic analysis tools that process untrusted packet data from network interfaces or packet capture files.
From an operational perspective, this vulnerability poses significant risks to network security monitoring and analysis environments where tcpdump serves as a primary packet inspection tool. Security operations centers, network administrators, and penetration testers who rely on tcpdump for network traffic analysis may be vulnerable to remote code execution attacks if they process untrusted packet captures or network traffic containing maliciously crafted packets. The impact extends beyond simple application crashes to potentially enable privilege escalation or complete system compromise, particularly when tcpdump runs with elevated privileges during network monitoring operations. This vulnerability directly affects the integrity and availability of network monitoring infrastructure, potentially compromising the security posture of organizations relying on tcpdump for traffic analysis.
Mitigation strategies for CVE-2017-5342 involve immediate upgrading to tcpdump version 4.9.0 or later, which includes proper bounds checking and input validation for the affected protocol parsers. Organizations should also implement network segmentation and access controls to limit exposure of tcpdump instances to untrusted network traffic, while maintaining regular patch management procedures for network security tools. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of improper input validation that enables memory corruption attacks. From an ATT&CK framework perspective, this vulnerability could be leveraged during the execution phase of an attack, potentially allowing adversaries to gain unauthorized access to systems through network monitoring tools that process malicious packet data. Security teams should also consider implementing network traffic filtering rules to prevent processing of suspicious protocol headers and maintain comprehensive logging of tcpdump operations to detect potential exploitation attempts.