CVE-2016-7932 in macOS
Summary
by MITRE
The PIM parser in tcpdump before 4.9.0 has a buffer overflow in print-pim.c:pimv2_check_checksum().
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 05/16/2026
The vulnerability identified as CVE-2016-7932 represents a critical buffer overflow flaw within the Protocol Independent Multicast PIM parser of tcpdump software versions prior to 4.9.0. This issue specifically manifests in the print-pim.c source file at the pimv2_check_checksum() function, where insufficient input validation and bounds checking allow maliciously crafted PIM packets to trigger memory corruption. The buffer overflow occurs when tcpdump processes multicast routing protocol packets that follow the PIM version 2 specification, making this vulnerability particularly dangerous in network environments where multicast traffic is prevalent. The flaw stems from inadequate handling of packet data length validation during the checksum verification process, creating an opportunity for attackers to exploit memory corruption through carefully constructed malicious PIM packets.
The technical implementation of this vulnerability follows a classic buffer overflow pattern where the software fails to properly validate the size of incoming PIM packet data before copying it into fixed-size buffers. This allows an attacker to overflow the allocated memory space and potentially overwrite adjacent memory locations, including function return addresses and control data. The vulnerability is particularly concerning because PIM is widely used in enterprise networks for multicast routing, making the attack surface extensive across various network infrastructure components. The flaw operates at the network protocol parsing layer, meaning that any system running vulnerable tcpdump versions and processing PIM packets could be compromised, regardless of the underlying operating system or network topology. This type of vulnerability aligns with CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking allows memory to be overwritten.
The operational impact of CVE-2016-7932 extends beyond simple denial of service scenarios to potentially enable remote code execution in certain configurations. When exploited, the buffer overflow could allow attackers to execute arbitrary code on systems running vulnerable tcpdump versions, particularly those monitoring multicast traffic. Network administrators who rely on tcpdump for network monitoring and security analysis face significant risk, as the vulnerability could be leveraged to gain unauthorized access to network monitoring systems. The attack vector requires the attacker to have network access to inject malicious PIM packets into the monitored network segment, making this vulnerability particularly relevant in environments where network monitoring tools are deployed. This aligns with ATT&CK technique T1059, where adversaries may execute code through network-based attacks on monitoring systems.
Mitigation strategies for this vulnerability center on immediate software updates to tcpdump version 4.9.0 or later, which contains the necessary patches to address the buffer overflow in the PIM parser. System administrators should prioritize patching network monitoring infrastructure, particularly devices running tcpdump in promiscuous mode or monitoring multicast traffic. Additional protective measures include implementing network segmentation to limit access to multicast routing protocols, deploying intrusion detection systems that can identify malformed PIM packets, and configuring firewalls to filter suspicious multicast traffic. Organizations should also consider implementing network monitoring solutions that can detect anomalous PIM packet behavior and provide real-time alerts when potentially malicious traffic patterns are identified. The vulnerability demonstrates the importance of regular security updates and proper input validation in network protocol parsers, as highlighted in industry best practices for secure software development and network security operations.