CVE-2017-12895 in macOS
Summary
by MITRE
The ICMP parser in tcpdump before 4.9.2 has a buffer over-read in print-icmp.c:icmp_print().
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Analysis
by VulDB Data Team • 12/04/2025
The vulnerability identified as CVE-2017-12895 represents a critical buffer over-read flaw within the ICMP parser component of tcpdump versions prior to 4.9.2. This issue resides specifically in the print-icmp.c source file within the icmp_print() function, where improper input validation allows for memory access beyond allocated buffer boundaries. The vulnerability manifests when tcpdump processes malformed or crafted ICMP packets during network traffic analysis, creating a potential avenue for denial of service or arbitrary code execution depending on the execution context.
This buffer over-read vulnerability falls under the Common Weakness Enumeration category of CWE-125, which describes "Out-of-bounds Read" conditions where software attempts to read data beyond the boundaries of a buffer. The flaw occurs during the parsing of Internet Control Message Protocol packets, which are fundamental to network diagnostics and error reporting in ip networks. When tcpdump encounters ICMP packets with unexpected or malformed structures, the icmp_print() function fails to properly validate packet lengths and header offsets, leading to memory corruption that can be exploited by attackers who control network traffic.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it can potentially enable remote code execution in environments where tcpdump is executed with elevated privileges. Network administrators and security professionals who rely on tcpdump for packet analysis and network monitoring face significant risk, as an attacker could craft malicious ICMP packets that trigger the buffer over-read condition. This vulnerability affects any system running tcpdump versions earlier than 4.9.2, particularly those in production environments where network monitoring tools process untrusted network traffic without proper sanitization.
The technical exploitation of this vulnerability requires an attacker to craft specially formatted ICMP packets that cause tcpdump to read memory locations beyond the intended buffer boundaries. This typically involves manipulating packet headers or payload data to exceed expected length parameters during parsing operations. The ATT&CK framework categorizes this type of vulnerability under T1059 for command and scripting interpreter and T1133 for external remote services, as it represents a potential entry point for attackers seeking to compromise network monitoring systems. Organizations using tcpdump for security monitoring, intrusion detection, or network forensics are particularly vulnerable since these tools often run with elevated privileges and process large volumes of network traffic.
Mitigation strategies for CVE-2017-12895 primarily involve upgrading to tcpdump version 4.9.2 or later, which includes proper bounds checking and input validation within the icmp_print() function. System administrators should also implement network segmentation and access controls to limit exposure of systems running tcpdump to untrusted network traffic. Additional protective measures include deploying network intrusion prevention systems that can detect and block malformed ICMP traffic, implementing proper packet filtering rules at network boundaries, and conducting regular security assessments to identify potentially vulnerable network monitoring infrastructure. Organizations should also consider implementing network traffic analysis tools that perform additional validation beyond the basic tcpdump functionality to provide layered protection against similar vulnerabilities.