CVE-2019-8376 in tcpreplay
Summary
by MITRE
An issue was discovered in Tcpreplay 4.3.1. A NULL pointer dereference occurred in the function get_layer4_v6() located at get.c. This can be triggered by sending a crafted pcap file to the tcpreplay-edit binary. It allows an attacker to cause a Denial of Service (Segmentation fault) or possibly have unspecified other impact.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 07/10/2023
The vulnerability identified as CVE-2019-8376 represents a critical NULL pointer dereference flaw within Tcpreplay version 4.3.1, specifically within the get_layer4_v6() function located in the get.c source file. This issue arises from inadequate input validation and error handling mechanisms when processing crafted pcap files through the tcpreplay-edit binary utility. The vulnerability exists in the context of network packet analysis and replay tools that are commonly used for testing network infrastructure, performing security assessments, and validating network protocols. Tcpreplay is widely utilized in cybersecurity operations, network administration, and penetration testing environments where accurate packet replay functionality is essential for various operational tasks.
The technical exploitation of this vulnerability occurs when a maliciously crafted pcap file is processed by the tcpreplay-edit binary, triggering the NULL pointer dereference in the get_layer4_v6() function. This function is responsible for extracting and processing Layer 4 information from IPv6 packets during packet analysis. When the function encounters malformed or specially crafted packet data that does not conform to expected packet structures, it fails to properly validate pointer references before dereferencing them, resulting in a segmentation fault that terminates the application process. The flaw stems from insufficient defensive programming practices and lacks proper null checks before pointer operations, making it susceptible to exploitation through crafted input data. This type of vulnerability falls under CWE-476 which specifically addresses NULL pointer dereference conditions in software implementations.
The operational impact of CVE-2019-8376 extends beyond simple denial of service conditions, as it can potentially enable more sophisticated attack vectors depending on the execution environment. When exploited successfully, the vulnerability causes a segmentation fault that results in application termination, effectively denying service to legitimate users who rely on tcpreplay for network testing and analysis. In environments where tcpreplay is used for automated network testing, continuous monitoring, or security validation processes, this vulnerability can lead to significant operational disruptions. The potential for unspecified other impacts suggests that under certain conditions, the NULL pointer dereference might be exploitable for more advanced attacks such as memory corruption or information disclosure, though the primary documented impact remains denial of service. This vulnerability directly affects the availability and reliability of network analysis tools that security professionals depend upon for their operations.
Mitigation strategies for CVE-2019-8376 should focus on immediate patching and implementation of defensive measures. Organizations should prioritize updating to Tcpreplay versions that contain fixes for this vulnerability, as the upstream maintainers have released patches that address the NULL pointer dereference issue through proper input validation and null pointer checks. Additionally, implementing proper input sanitization measures when processing pcap files, including validation of packet structures and content before processing, can help prevent exploitation. Network security teams should also consider deploying monitoring solutions that can detect anomalous packet processing patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of defensive programming practices and proper error handling in security tools, particularly those handling untrusted network data. From an ATT&CK framework perspective, this vulnerability could be categorized under technique T1499 for network disruption and potentially T1059 for command and control through compromised tools, though the primary impact remains focused on availability disruption. System administrators should also implement least privilege principles when running tcpreplay utilities and consider sandboxing execution environments to limit potential impact if exploitation occurs.