CVE-2019-15166 in tcpdump
Summary
by MITRE
lmp_print_data_link_subobjs() in print-lmp.c in tcpdump before 4.9.3 lacks certain bounds checks.
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Analysis
by VulDB Data Team • 12/03/2025
The vulnerability identified as CVE-2019-15166 resides within the tcpdump network packet analysis tool, specifically in the lmp_print_data_link_subobjs() function located in print-lmp.c. This issue affects tcpdump versions prior to 4.9.3 and represents a classic buffer overread condition that can lead to arbitrary code execution or system compromise. The vulnerability stems from insufficient bounds checking mechanisms within the function responsible for parsing Link Management Protocol (LMP) data link subobjects during packet analysis operations.
The technical flaw manifests when tcpdump processes network packets containing malformed LMP data structures. The lmp_print_data_link_subobjs() function fails to validate the length of data subobjects before attempting to read beyond the allocated buffer boundaries. This oversight creates a scenario where an attacker can craft specially malformed network packets that trigger memory access violations when tcpdump attempts to parse the LMP subobjects. The missing bounds checks allow for potential memory corruption that can be exploited to execute arbitrary code with the privileges of the user running tcpdump.
From an operational impact perspective, this vulnerability poses significant risks to network monitoring and security operations that rely on tcpdump for packet analysis. Network administrators and security analysts who use tcpdump for traffic inspection, intrusion detection, or forensic analysis are at risk when processing untrusted network traffic. The vulnerability can be exploited remotely through network packet capture operations, making it particularly dangerous in environments where tcpdump is used to analyze network traffic from untrusted sources. The attack surface expands when considering that tcpdump is commonly deployed in security operations centers, network monitoring systems, and forensic analysis environments where it processes diverse packet streams.
The vulnerability aligns with CWE-129, which addresses insufficient bounds checking, and represents a variant of the broader class of buffer overread conditions that can lead to memory corruption. From an ATT&CK framework perspective, this vulnerability maps to techniques involving execution through command-line interfaces and privilege escalation through software exploitation. The weakness can be leveraged by adversaries to establish persistent access or conduct more sophisticated attacks by compromising the integrity of network monitoring tools.
Mitigation strategies for CVE-2019-15166 primarily involve upgrading to tcpdump version 4.9.3 or later, which includes the necessary bounds checking mechanisms. Organizations should also implement network segmentation and access controls to limit exposure to potentially malicious traffic, while monitoring for suspicious packet patterns that might indicate exploitation attempts. Additionally, deploying intrusion detection systems that can identify malformed LMP traffic and implementing network access control lists to filter suspicious packets can provide additional layers of defense. Regular security assessments and vulnerability scanning should be conducted to ensure that tcpdump installations remain current with security patches and that network monitoring infrastructure maintains robust security postures against similar vulnerabilities.