CVE-2017-12901 in macOS
Summary
by MITRE
The EIGRP parser in tcpdump before 4.9.2 has a buffer over-read in print-eigrp.c:eigrp_print().
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Analysis
by VulDB Data Team • 12/04/2025
The vulnerability identified as CVE-2017-12901 represents a critical buffer over-read flaw within the Enhanced Interior Gateway Routing Protocol parser of tcpdump software. This issue exists in versions prior to 4.9.2 and specifically affects the print-eigrp.c module where the eigrp_print() function handles EIGRP packet processing. The flaw manifests when tcpdump attempts to parse EIGRP packets, which are commonly used in Cisco networking environments for dynamic routing protocols. EIGRP packets contain various fields including header information, TLV (Type-Length-Value) structures, and payload data that the parser must correctly interpret for network monitoring and analysis purposes.
The technical nature of this vulnerability stems from insufficient bounds checking within the EIGRP packet parsing logic. When tcpdump encounters an EIGRP packet with malformed or unexpected data structures, the eigrp_print() function fails to properly validate buffer boundaries before reading data from memory locations beyond the intended packet boundaries. This over-read condition occurs because the parser assumes certain packet structures and field lengths without adequate validation mechanisms. The vulnerability is particularly concerning as it can be triggered through network packet capture activities, making it exploitable in environments where tcpdump is used for network monitoring and troubleshooting.
From an operational impact perspective, this vulnerability creates significant security risks for network administrators who rely on tcpdump for traffic analysis and network diagnostics. An attacker could potentially craft malicious EIGRP packets designed to trigger the buffer over-read condition, leading to application crashes, denial of service conditions, or potentially more severe consequences depending on the execution environment. The vulnerability affects any system running tcpdump versions before 4.9.2 when processing EIGRP traffic, which is common in enterprise network environments using Cisco routers and switches. This flaw could be exploited in man-in-the-middle scenarios or during network reconnaissance activities where attackers attempt to disrupt network monitoring tools or gain unauthorized access to network information.
The vulnerability aligns with CWE-125, which describes "Out-of-bounds Read" conditions where programs access memory locations beyond the bounds of allocated buffers. This weakness is classified under the broader category of memory safety issues and represents a common class of vulnerabilities that can lead to system instability and potential exploitation. From an attack framework perspective, this vulnerability could be categorized under ATT&CK technique T1046 for network service scanning and T1490 for exploitation of remote services, as it affects network monitoring tools that are essential for maintaining network security posture. The flaw demonstrates the importance of proper input validation and bounds checking in network protocol parsers, which are critical components for network security monitoring and incident response activities.
Organizations should immediately upgrade to tcpdump version 4.9.2 or later to address this vulnerability, as the fix includes proper bounds checking mechanisms within the EIGRP packet parsing logic. Additionally, network administrators should consider implementing network segmentation and monitoring controls to detect and prevent exploitation attempts. The vulnerability highlights the need for comprehensive security testing of network monitoring tools and emphasizes the critical importance of keeping network infrastructure components updated with the latest security patches. Regular vulnerability assessments and penetration testing should include evaluation of network protocol parsers to identify similar buffer over-read conditions that could potentially be exploited in similar network monitoring tools and security applications.