CVE-2023-4256 in TCPrewrite
Summary
by MITRE • 12/21/2023
Within tcpreplay's tcprewrite, a double free vulnerability has been identified in the tcpedit_dlt_cleanup() function within plugins/dlt_plugins.c. This vulnerability can be exploited by supplying a specifically crafted file to the tcprewrite binary. This flaw enables a local attacker to initiate a Denial of Service (DoS) attack.
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Analysis
by VulDB Data Team • 01/29/2025
The vulnerability identified as CVE-2023-4256 represents a critical double free condition within tcpreplay's tcprewrite utility, specifically within the tcpedit_dlt_cleanup() function located in plugins/dlt_plugins.c. This flaw exists in the tcpedit library's handling of data link type (DLT) cleanup operations, where improper memory management leads to the same memory block being freed twice. The vulnerability is particularly concerning as it affects a widely used network packet manipulation tool that processes and rewrites network traffic for testing and analysis purposes.
The technical exploitation of this vulnerability occurs when a local attacker provides a specially crafted input file to the tcprewrite binary, which then processes this malformed data through the tcpedit_dlt_cleanup() function. During normal operation, the function should properly manage memory allocation and deallocation for DLT-related structures, but due to the double free flaw, memory management routines attempt to free the same memory address twice. This condition typically results in heap corruption that can lead to program termination, making the utility unavailable for legitimate use. The vulnerability is classified under CWE-415 as an improper cleanup of memory, specifically manifesting as a double free error that violates fundamental memory management principles.
The operational impact of CVE-2023-4256 extends beyond simple denial of service, as it represents a potential vector for more sophisticated attacks within environments where tcpreplay is used for network testing and security analysis. In enterprise network security contexts, where tcpreplay is commonly employed for packet capture analysis, traffic replay, and testing network security appliances, this vulnerability could be exploited to disrupt critical network operations. The local nature of the attack means that an attacker must already have access to the system to exploit this vulnerability, but the potential for causing service disruption makes it particularly dangerous in environments where network analysis tools are frequently utilized. The flaw also aligns with ATT&CK technique T1070.004 for bypassing defenses through memory corruption attacks, making it relevant to defensive strategies focused on memory safety.
Mitigation strategies for CVE-2023-4256 should prioritize immediate patching of affected tcpreplay installations, as this represents a straightforward remediation that addresses the root cause of the double free condition. Organizations should also implement proper input validation and sanitization procedures when processing network packet files, particularly in automated environments where tcpreplay might be used in conjunction with other network security tools. Additionally, system administrators should consider implementing monitoring for abnormal process termination patterns that might indicate exploitation attempts, while maintaining up-to-date security patches across all network analysis tooling. The vulnerability underscores the importance of memory safety practices in network security tools and highlights the need for regular security assessments of commonly used utilities in enterprise environments.