CVE-2017-13690 in macOS
Summary
by MITRE
The IKEv2 parser in tcpdump before 4.9.2 has a buffer over-read in print-isakmp.c, several functions.
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Analysis
by VulDB Data Team • 09/10/2024
The vulnerability identified as CVE-2017-13690 represents a critical buffer over-read flaw within the Internet Key Exchange version 2 implementation of the tcpdump network analysis tool. This issue specifically affects tcpdump versions prior to 4.9.2 and resides within the print-isakmp.c source file where the IKEv2 parser processes incoming network packets. The vulnerability stems from inadequate input validation and bounds checking during the parsing of IKEv2 protocol messages, particularly when handling malformed or specially crafted ISAKMP payloads. The flaw allows an attacker to potentially trigger memory access violations that could lead to application crashes or, in more severe scenarios, arbitrary code execution. This vulnerability directly impacts network monitoring and security analysis operations where tcpdump is deployed as a packet capture and analysis tool.
The technical implementation of this vulnerability involves the IKEv2 parser's failure to properly validate the length of incoming ISAKMP payloads before attempting to read data from memory locations. When tcpdump processes IKEv2 messages, it assumes certain minimum lengths for various fields within the ISAKMP header structure. However, when encountering packets with malformed or truncated payload data, the parser continues to read beyond allocated buffer boundaries, resulting in over-read conditions. This over-read behavior manifests as the parser accessing memory locations that do not correspond to the intended data structure, potentially exposing sensitive information or causing unpredictable application behavior. The vulnerability operates at the protocol parsing layer, making it particularly dangerous as it can be triggered by any network traffic containing IKEv2 packets, regardless of whether the system is actively negotiating security associations.
From an operational impact perspective, this vulnerability poses significant risks to network security infrastructure that relies on tcpdump for monitoring and analysis purposes. Security operations centers, network administrators, and penetration testing teams who deploy tcpdump for network traffic analysis may inadvertently expose their systems to remote exploitation. The vulnerability can be exploited through passive network monitoring scenarios where an attacker simply needs to send specially crafted IKEv2 packets to a system running vulnerable tcpdump versions. This makes the attack surface particularly broad as any system running tcpdump in promiscuous mode or monitoring networks with IKEv2 traffic becomes a potential target. The vulnerability also affects network forensic analysis tools that depend on tcpdump's packet parsing capabilities, potentially compromising the integrity of security investigations and incident response procedures.
The mitigation strategy for CVE-2017-13690 primarily involves upgrading to tcpdump version 4.9.2 or later, which includes proper bounds checking and input validation for IKEv2 packet parsing. Network administrators should prioritize patching affected systems and verify that all tcpdump installations across their infrastructure have been updated to secure versions. Additionally, implementing network segmentation and access control measures can help limit the potential impact of exploitation attempts. Organizations should also consider deploying intrusion detection systems that can identify and block suspicious IKEv2 traffic patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-129, which describes improper validation of length of input buffers, and represents a classic example of how protocol parsing flaws can lead to memory corruption vulnerabilities. From an ATT&CK framework perspective, this vulnerability could be leveraged as part of initial access or privilege escalation techniques, particularly in environments where tcpdump is used for security monitoring and where attackers might attempt to disrupt network analysis operations or gain unauthorized access through compromised monitoring systems.
This vulnerability demonstrates the critical importance of proper input validation in network protocol parsers and highlights the potential for seemingly benign network monitoring tools to become attack vectors. The flaw underscores the need for comprehensive security testing of network analysis tools, particularly those handling complex protocol implementations with multiple message types and varying payload structures. Regular security assessments and vulnerability scanning of network infrastructure components should include verification of tcpdump and related network analysis tool versions to prevent exploitation of known vulnerabilities. The incident also emphasizes the necessity of maintaining up-to-date security patches across all network monitoring and analysis systems to protect against sophisticated attack techniques that exploit implementation flaws in widely used security tools.