CVE-2017-12993 in macOS
Summary
by MITRE
The Juniper protocols parser in tcpdump before 4.9.2 has a buffer over-read in print-juniper.c, several functions.
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Analysis
by VulDB Data Team • 12/05/2025
The vulnerability identified as CVE-2017-12993 affects the tcpdump network packet analysis tool, specifically targeting versions prior to 4.9.2. This issue resides within the Juniper protocols parser implementation in the print-juniper.c source file, where multiple functions exhibit buffer over-read conditions that can lead to arbitrary code execution or denial of service. The flaw represents a critical security weakness in network monitoring and analysis tools that are widely deployed across enterprise and network infrastructure environments.
The technical implementation of this vulnerability stems from improper bounds checking within the Juniper protocol parsing functions. When tcpdump processes network packets containing Juniper-specific protocol data, the parser fails to validate the length of incoming data against the allocated buffer space, resulting in memory access beyond intended boundaries. This buffer over-read condition occurs because the code assumes certain data structures will maintain specific sizes while processing Juniper protocol headers and payload data. According to CWE-129, this represents an implementation flaw where insufficient input validation leads to buffer over-read conditions that can be exploited by malicious actors to execute arbitrary code or cause system instability.
The operational impact of CVE-2017-12993 extends beyond simple denial of service scenarios, as the vulnerability can be leveraged for remote code execution when tcpdump is run in privileged modes or when processing untrusted network traffic. Network administrators who rely on tcpdump for security monitoring, intrusion detection, or network troubleshooting may find their systems compromised if attackers can craft malicious Juniper protocol packets that trigger the buffer over-read condition. The vulnerability affects systems where tcpdump is used in promiscuous mode or when analyzing network traffic from untrusted sources, making it particularly dangerous in enterprise environments where network monitoring tools are extensively deployed.
The exploitation of this vulnerability aligns with ATT&CK technique T1059.007 for command and script interpreter, as successful exploitation could allow attackers to execute arbitrary commands on affected systems. The vulnerability also relates to T1499.004 for network disruption through resource exhaustion, since buffer over-read conditions can lead to system crashes or memory corruption that impacts network monitoring capabilities. Organizations using tcpdump for network analysis should consider this vulnerability as part of their broader security posture assessment, particularly when the tool is deployed in environments where it processes untrusted network traffic or when it runs with elevated privileges.
Mitigation strategies for CVE-2017-12993 require immediate patching of tcpdump installations to version 4.9.2 or later, which contains the necessary fixes for the buffer over-read conditions. System administrators should also implement network segmentation and access controls to limit exposure of systems running tcpdump to untrusted network traffic. Additional defensive measures include deploying network monitoring tools that can detect and block malformed Juniper protocol packets, implementing proper input validation at network boundaries, and conducting regular vulnerability assessments to identify other potentially affected components in the network infrastructure stack. Organizations should also consider disabling tcpdump in production environments where it processes untrusted traffic and instead rely on more secure network analysis tools that properly validate input data before processing.