CVE-2017-13016 in macOS
Summary
by MITRE
The ISO ES-IS parser in tcpdump before 4.9.2 has a buffer over-read in print-isoclns.c:esis_print().
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Analysis
by VulDB Data Team • 12/05/2025
The vulnerability identified as CVE-2017-13016 represents a critical buffer over-read flaw within the tcpdump network analysis tool that affects versions prior to 4.9.2. This issue resides within the ISO ES-IS (End System to Intermediate System) protocol parser implementation, specifically in the print-isoclns.c source file where the esis_print() function executes. The flaw occurs when tcpdump processes network packets containing ISO ES-IS protocol data, creating a scenario where the parser reads beyond the allocated buffer boundaries. This type of vulnerability falls under the CWE-125 category of Out-of-Bounds Read, which represents a fundamental memory safety issue that can lead to unpredictable behavior and potential exploitation. The vulnerability is particularly concerning because tcpdump is widely deployed across network security monitoring and forensic analysis environments, making it a prime target for attackers seeking to compromise network monitoring infrastructure.
The technical execution of this buffer over-read vulnerability occurs during the parsing of ISO ES-IS packets within the esis_print() function, which is responsible for displaying the contents of these network protocol messages. When processing malformed or specially crafted ISO ES-IS protocol packets, the parser fails to properly validate the length of data structures before reading from memory locations beyond the intended buffer boundaries. This over-read condition can result in the parser accessing uninitialized memory, potentially exposing sensitive information from adjacent memory regions or causing application crashes that lead to denial of service conditions. The issue stems from inadequate input validation within the protocol parser, where the code assumes certain data structures will maintain specific sizes without proper bounds checking, creating an exploitable condition that aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter.
The operational impact of CVE-2017-13016 extends beyond simple denial of service scenarios, as this vulnerability can be leveraged by attackers to gain unauthorized access to network monitoring systems or to extract sensitive information from memory. Network administrators and security analysts who rely on tcpdump for traffic analysis and incident response may find their monitoring capabilities compromised when attackers exploit this vulnerability to disrupt network analysis operations. The vulnerability's presence in widely-used network monitoring tools means that exploitation could affect multiple organizations simultaneously, particularly those with legacy systems running older versions of tcpdump. Organizations using tcpdump for security monitoring, network troubleshooting, and forensic analysis are at risk of having their tools rendered unreliable or potentially compromised, creating gaps in network visibility that attackers can exploit. The vulnerability's classification as a buffer over-read also makes it susceptible to exploitation patterns described in the ATT&CK framework under T1499 for Network Denial of Service and T1005 for Data from Local System, highlighting the multi-faceted nature of the threat.
Mitigation strategies for CVE-2017-13016 primarily focus on updating tcpdump to version 4.9.2 or later, which contains the necessary patches to address the buffer over-read condition in the esis_print() function. System administrators should prioritize patching all instances of tcpdump across their network infrastructure, particularly those deployed in security monitoring roles where the vulnerability could be exploited to compromise network visibility. Additionally, implementing network segmentation and access controls can help limit the potential impact of exploitation by reducing the attack surface for vulnerable tcpdump installations. Organizations should also consider deploying network monitoring tools that have been updated to address this specific vulnerability, ensuring that their security infrastructure remains robust against known threats. The vulnerability serves as a reminder of the importance of maintaining up-to-date network security tools and implementing proper input validation in protocol parsers to prevent similar issues from arising in the future. Regular vulnerability assessments and security audits should include checks for outdated network monitoring tools that may contain unpatched buffer over-read vulnerabilities, as these can create significant security gaps in network defense strategies.