CVE-2018-14882 in tcpdump
Summary
by MITRE
The ICMPv6 parser in tcpdump before 4.9.3 has a buffer over-read in print-icmp6.c.
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Analysis
by VulDB Data Team • 12/03/2025
The vulnerability identified as CVE-2018-14882 represents a critical buffer over-read flaw within the ICMPv6 parsing functionality of tcpdump versions prior to 4.9.3. This issue resides specifically within the print-icmp6.c source file, which handles the interpretation and display of Internet Control Message Protocol version 6 packets. The flaw occurs when tcpdump processes malformed or crafted ICMPv6 packets that contain insufficient data in their headers or payload structures, leading to attempts to read memory locations beyond the allocated buffer boundaries. Such over-read conditions can result in information disclosure, application crashes, or potentially more severe consequences depending on the execution environment and memory layout.
This vulnerability falls under the CWE-125 category of Out-of-Bounds Read, which is classified as a fundamental memory safety issue in software development. The technical implementation flaw manifests when the ICMPv6 parser does not properly validate the length of incoming packet data before attempting to access specific fields within the packet structure. The parser assumes that certain minimum data lengths exist within the ICMPv6 header and payload, but malicious or malformed packets can violate these assumptions, causing the program to read beyond the intended buffer limits. This behavior creates an attack surface where an adversary could potentially craft specific ICMPv6 packets to trigger the over-read condition, leading to unpredictable program behavior and potential exploitation.
The operational impact of CVE-2018-14882 extends beyond simple application instability, particularly in network monitoring and security analysis environments where tcpdump serves as a critical tool. When deployed in production network security monitoring systems, such as intrusion detection systems or network traffic analysis platforms, the vulnerability could be exploited to cause denial of service conditions or information leakage. The over-read behavior might expose sensitive memory contents including cryptographic keys, session tokens, or other confidential data residing in adjacent memory regions. Network administrators and security professionals who rely on tcpdump for traffic analysis and forensic investigations face potential risks where attackers could leverage this vulnerability to disrupt monitoring operations or extract valuable information from the monitoring infrastructure.
From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1046 which involves the use of network service scanning to identify active systems and services. Attackers could potentially use this flaw in conjunction with other techniques to establish persistent access or conduct more sophisticated reconnaissance activities. The vulnerability is particularly concerning in environments where tcpdump is used for continuous network monitoring, as the over-read condition could be triggered by legitimate network traffic or crafted attack packets, making detection and mitigation challenging. Organizations should consider implementing network segmentation and access controls to limit exposure, while also ensuring that tcpdump installations are updated to version 4.9.3 or later to eliminate the risk of exploitation. The fix implemented in tcpdump 4.9.3 addresses the root cause by adding proper bounds checking and validation of packet data lengths before attempting to access memory regions, thereby preventing the buffer over-read condition from occurring.