CVE-2016-7175 in Wireshark
Summary
by MITRE
epan/dissectors/packet-qnet6.c in the QNX6 QNET dissector in Wireshark 2.x before 2.0.6 mishandles MAC address data, which allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via a crafted packet.
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Analysis
by VulDB Data Team • 09/15/2022
The vulnerability identified as CVE-2016-7175 resides within the QNX6 QNET dissector component of Wireshark version 2.x prior to 2.0.6. This flaw manifests in the epan/dissectors/packet-qnet6.c file where the software fails to properly validate MAC address data during packet processing. The issue represents a classic buffer over-read condition that occurs when the dissector attempts to parse malformed network packets containing crafted MAC address information. Such improper input handling creates a scenario where an attacker can manipulate the dissector's behavior by sending specifically constructed packets that exploit the lack of bounds checking in the MAC address parsing routine.
The technical implementation of this vulnerability stems from insufficient validation of packet data within the QNX6 protocol dissector module. When Wireshark processes network traffic containing QNET protocol packets, the dissector routine in packet-qnet6.c attempts to extract and interpret MAC address information without adequate bounds checking. This allows an attacker to craft packets with malformed MAC address fields that exceed the expected data boundaries, causing the application to read memory locations beyond the allocated buffer space. The out-of-bounds memory access results in unpredictable application behavior including segmentation faults, memory corruption, and ultimately application crashes that terminate the Wireshark process.
The operational impact of CVE-2016-7175 presents significant denial of service risks for network monitoring and analysis operations. Remote attackers can exploit this vulnerability to disrupt network analysis workflows by causing Wireshark to crash whenever it encounters a crafted packet, effectively rendering the network monitoring tool unavailable for legitimate analysis tasks. This vulnerability is particularly concerning in environments where Wireshark serves as a critical component for network troubleshooting, security monitoring, or forensic analysis, as the disruption can impede network operations and potentially mask malicious activities. The vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and can be categorized under ATT&CK technique T1499.1 for network denial of service attacks. The flaw demonstrates how protocol dissector components in network analysis tools can become attack vectors when proper input validation is absent.
Mitigation strategies for CVE-2016-7175 require immediate application of the vendor-provided security patch that updates the QNX6 QNET dissector to properly validate MAC address data and implement appropriate bounds checking. Organizations should prioritize updating their Wireshark installations to version 2.0.6 or later where this vulnerability has been addressed through enhanced input validation mechanisms. Network administrators should also consider implementing network segmentation and access controls to limit exposure to potentially malicious packet traffic. Additionally, deploying intrusion detection systems that can identify and block suspicious packet patterns may provide an additional layer of protection against exploitation attempts. The fix implemented by Wireshark developers involved strengthening the input validation logic in the packet-qnet6.c file to ensure that MAC address data remains within expected boundaries, preventing the out-of-bounds memory read conditions that previously caused application crashes.