CVE-2016-7938 in macOS
Summary
by MITRE
The ZeroMQ parser in tcpdump before 4.9.0 has an integer overflow in print-zeromq.c:zmtp1_print_frame().
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Analysis
by VulDB Data Team • 05/16/2026
The vulnerability identified as CVE-2016-7938 represents a critical integer overflow flaw within the ZeroMQ message parser implementation of tcpdump version 4.8.2 and earlier. This issue specifically affects the zmtp1_print_frame() function located in the print-zeromq.c source file, which is responsible for parsing and displaying ZeroMQ message frames during network packet analysis. The integer overflow occurs when processing malformed ZeroMQ frames, potentially leading to unpredictable behavior and system instability.
The technical nature of this vulnerability stems from improper input validation and arithmetic handling within the frame length parsing logic. When tcpdump encounters a ZeroMQ frame with an excessively large or malformed length field, the parser fails to properly validate the integer values before performing arithmetic operations. This allows an attacker to craft malicious network packets containing oversized frame headers that cause integer overflow conditions, potentially resulting in buffer overflows, memory corruption, or arbitrary code execution. The vulnerability aligns with CWE-190, which specifically addresses integer overflow conditions, and represents a classic example of how improper integer handling can lead to severe security implications in network analysis tools.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it can potentially enable remote code execution on systems running vulnerable versions of tcpdump. Attackers could exploit this flaw by transmitting specially crafted ZeroMQ frames to a target system that is actively monitoring network traffic with tcpdump. The consequences include potential system compromise, data exfiltration, and complete loss of network monitoring capabilities. Given that tcpdump is widely deployed across network infrastructure and security monitoring systems, this vulnerability poses a significant risk to enterprise networks and security operations centers that rely on proper packet analysis capabilities.
Mitigation strategies for CVE-2016-7938 primarily focus on immediate software updates to tcpdump version 4.9.0 or later, which contains the necessary patches to address the integer overflow condition. System administrators should prioritize patching all network monitoring systems, intrusion detection systems, and security tools that utilize vulnerable tcpdump versions. Additionally, network segmentation and access control measures should be implemented to limit exposure to potentially malicious traffic. Organizations should also consider implementing network traffic filtering rules that can detect and block suspicious ZeroMQ frame patterns, though this approach provides only partial protection. The vulnerability demonstrates the importance of maintaining up-to-date security tools and highlights the need for robust input validation in network protocol parsers, aligning with ATT&CK technique T1059.007 for execution through network protocols and T1566.001 for initial access via network protocols.