CVE-2016-7930 in macOS
Summary
by MITRE
The LLC/SNAP parser in tcpdump before 4.9.0 has a buffer overflow in print-llc.c:llc_print().
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Analysis
by VulDB Data Team • 05/16/2026
The vulnerability identified as CVE-2016-7930 represents a critical buffer overflow flaw within the tcpdump network analysis tool that affects versions prior to 4.9.0. This issue resides in the LLC/SNAP (Logical Link Control/Subnetwork Access Protocol) packet parser implementation, specifically within the print-llc.c source file at the llc_print() function. The vulnerability arises from insufficient input validation and bounds checking when processing malformed LLC/SNAP frames, creating an exploitable condition that can be triggered by capturing and analyzing specially crafted network traffic.
The technical flaw manifests when tcpdump processes network packets containing malformed LLC/SNAP headers that exceed the allocated buffer space during parsing operations. This buffer overflow occurs because the llc_print() function fails to properly validate the length of incoming LLC/SNAP frame data before copying it into fixed-size internal buffers. The vulnerability is categorized under CWE-121 as a stack-based buffer overflow, where attacker-controlled data can overwrite adjacent memory locations, potentially leading to arbitrary code execution or application crash. The LLC/SNAP protocol is commonly used in various network environments including wireless networks, token ring networks, and certain enterprise network configurations, making this vulnerability particularly concerning for network monitoring tools.
The operational impact of CVE-2016-7930 extends beyond simple denial of service scenarios, as it presents significant security risks to network monitoring infrastructure. When exploited, this vulnerability can allow remote attackers to execute arbitrary code on systems running vulnerable versions of tcpdump, potentially leading to complete system compromise. The attack surface is broad since tcpdump is widely deployed across enterprise networks for packet capture and analysis, making it a prime target for adversaries seeking to gain unauthorized access to network monitoring systems. This vulnerability directly aligns with ATT&CK technique T1046 for network service scanning and T1059 for command and scripting interpreter usage, as it enables attackers to compromise network monitoring capabilities and potentially pivot to other network segments.
Mitigation strategies for CVE-2016-7930 primarily focus on immediate version updates to tcpdump 4.9.0 or later, which contain the necessary patches to address the buffer overflow condition. Organizations should also implement network segmentation and access controls to limit exposure of tcpdump instances to untrusted network traffic, while maintaining proper network monitoring for suspicious packet patterns that might indicate exploitation attempts. Additionally, deploying intrusion detection systems with signature-based detection capabilities that can identify malformed LLC/SNAP packets can provide additional layers of defense. The vulnerability highlights the importance of regular security updates and proper input validation in network security tools, as inadequate bounds checking in protocol parsers can create persistent security risks that affect critical infrastructure components.