CVE-2017-13005 in macOS
Summary
by MITRE
The NFS parser in tcpdump before 4.9.2 has a buffer over-read in print-nfs.c:xid_map_enter().
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Analysis
by VulDB Data Team • 09/07/2024
The vulnerability identified as CVE-2017-13005 represents a critical buffer over-read flaw within the Network File System (NFS) parser implementation of tcpdump version 4.9.2 and earlier. This issue specifically manifests in the print-nfs.c source file at the xid_map_enter() function, where improper input validation leads to memory access violations that can potentially be exploited by malicious actors. The flaw occurs during network packet analysis when tcpdump processes NFS protocol traffic, making it particularly dangerous in network monitoring and security auditing environments where the tool is commonly deployed.
The technical implementation of this vulnerability stems from inadequate bounds checking within the xid_map_enter() function which handles the mapping of NFS transaction identifiers. When tcpdump encounters NFS packets during network capture, the parser attempts to process the transaction ID field without sufficient validation of buffer boundaries. This allows an attacker to craft specially malformed NFS packets that cause the parser to read beyond allocated memory boundaries, potentially exposing sensitive data or causing application crashes. The vulnerability is classified under CWE-129 as an Improper Validation of Array Index, specifically manifesting as an out-of-bounds read condition that violates memory safety principles fundamental to secure software development practices.
The operational impact of this vulnerability extends beyond simple application instability, as it can be leveraged in various attack scenarios within network security contexts. An attacker positioned to inject malicious NFS traffic into a monitored network segment could potentially exploit this flaw to cause denial of service conditions, leading to complete tcpdump process termination and disruption of network monitoring capabilities. Furthermore, the over-read condition may expose sensitive memory contents to unauthorized parties, creating potential information disclosure risks that could compromise network security monitoring operations. This vulnerability particularly affects environments where tcpdump is used for security auditing, network forensics, and intrusion detection, as the tool's failure could leave critical network visibility gaps.
Mitigation strategies for CVE-2017-13005 focus primarily on immediate software updates and deployment of patched tcpdump versions. System administrators should prioritize updating to tcpdump 4.9.2 or later releases where the buffer over-read has been corrected through proper bounds checking implementations. Additionally, network security teams should consider implementing network segmentation and access controls to limit exposure to potentially malicious NFS traffic, while monitoring for unusual packet patterns that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1046 for Network Service Scanning and T1499 for Endpoint Termination, making it relevant to both reconnaissance and attack execution phases in cybersecurity frameworks. Organizations should also implement regular vulnerability scanning procedures to identify unpatched systems and ensure comprehensive network security posture maintenance.