CVE-2017-13033 in macOS
Summary
by MITRE
The VTP parser in tcpdump before 4.9.2 has a buffer over-read in print-vtp.c:vtp_print().
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 01/06/2023
The vulnerability identified as CVE-2017-13033 represents a critical buffer over-read flaw within the VLAN Trunking Protocol parser of tcpdump version 4.9.1 and earlier. This issue specifically affects the print-vtp.c component where the vtp_print() function processes incoming network packets containing VTP protocol data. The vulnerability arises from insufficient input validation and bounds checking during packet parsing operations, creating an exploitable condition that can lead to arbitrary code execution or system instability. The flaw exists in the network protocol analysis tool commonly used by security professionals and network administrators for packet capture and analysis, making it particularly concerning given the widespread adoption of tcpdump in network monitoring environments.
The technical implementation of this vulnerability stems from improper handling of variable-length data structures within the VTP protocol parsing logic. When tcpdump processes VTP packets, the vtp_print() function attempts to read data beyond the allocated buffer boundaries without adequate validation of packet length or content integrity. This over-read condition occurs because the parser assumes certain data fields will contain predictable amounts of data while failing to verify that incoming packets conform to expected format specifications. The vulnerability is categorized under CWE-125 as an out-of-bounds read, which is a well-known class of memory safety issues that can lead to information disclosure, denial of service, or potentially remote code execution depending on the system configuration and memory layout.
From an operational perspective, this vulnerability presents significant risks to network monitoring and security operations. Attackers can craft malicious VTP packets that trigger the buffer over-read condition when processed by vulnerable tcpdump instances, potentially causing the application to crash or behave unpredictably. In environments where tcpdump is used for continuous network monitoring, this vulnerability could be exploited to cause denial of service attacks against network infrastructure monitoring systems. The impact extends beyond simple service disruption as the over-read condition may expose sensitive memory contents to attackers, potentially revealing system information, credentials, or other confidential data that could be leveraged for further exploitation. This vulnerability aligns with ATT&CK technique T1046 for network service scanning and T1499 for network denial of service, representing both reconnaissance and attack capabilities within network security frameworks.
Mitigation strategies for CVE-2017-13033 primarily focus on upgrading to tcpdump version 4.9.2 or later, which includes proper bounds checking and input validation for VTP packet parsing. Network administrators should also implement network segmentation and access controls to limit exposure of tcpdump instances to untrusted network traffic. Additional protective measures include deploying intrusion detection systems that can identify and block malformed VTP packets, implementing network monitoring alerts for unusual tcpdump behavior, and conducting regular security assessments to ensure all network analysis tools remain updated. Organizations should also consider implementing network access control lists to prevent unauthorized VTP traffic from reaching systems running tcpdump, reducing the attack surface for this specific vulnerability while maintaining operational security monitoring capabilities.