CVE-2017-13049 in macOS
Summary
by MITRE
The Rx protocol parser in tcpdump before 4.9.2 has a buffer over-read in print-rx.c:ubik_print().
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Analysis
by VulDB Data Team • 09/09/2024
The vulnerability identified as CVE-2017-13049 represents a critical buffer over-read flaw within the Rx protocol parser of tcpdump software versions prior to 4.9.2. This issue specifically manifests in the ubik_print() function located in the print-rx.c source file, where inadequate input validation and memory boundary checking allows attackers to exploit malformed network packets. The Rx protocol is commonly used in distributed computing environments, particularly within the Andrew File System and related distributed applications, making this vulnerability particularly concerning for network security infrastructure. The flaw occurs when tcpdump processes network traffic containing specially crafted Rx protocol packets, leading to memory access violations that could potentially be leveraged for denial of service or arbitrary code execution.
The technical implementation of this vulnerability stems from improper handling of packet data structures within the ubik_print() function, which fails to validate the length of incoming data before attempting to read beyond allocated buffer boundaries. This type of flaw falls under the CWE-125 vulnerability category, which specifically addresses out-of-bounds read conditions in software implementations. The vulnerability is particularly dangerous because it operates at the packet parsing layer of tcpdump, meaning that any network traffic containing malformed Rx protocol data could trigger the over-read condition. Attackers could exploit this by crafting malicious packets that, when processed by an affected tcpdump instance, would cause the application to access memory locations beyond the intended buffer limits, potentially leading to application crashes or more severe security consequences.
The operational impact of CVE-2017-13049 extends beyond simple denial of service scenarios, as the vulnerability could enable more sophisticated attack vectors within network monitoring and security analysis environments. Systems running vulnerable versions of tcpdump, particularly those used for network traffic analysis, intrusion detection, or security auditing, become susceptible to exploitation when processing network packets containing the malicious Rx protocol data. This vulnerability affects organizations that rely on tcpdump for network forensics, security monitoring, or packet analysis, as any compromised monitoring system could be rendered ineffective or potentially compromised. The ATT&CK framework categorizes this type of vulnerability under the T1059 technique, as it involves the exploitation of application-level parsing flaws that could lead to command injection or system compromise.
Organizations should immediately implement mitigations including upgrading to tcpdump version 4.9.2 or later, which contains the necessary patches to address the buffer over-read condition in the Rx protocol parser. Additionally, network administrators should consider implementing network segmentation and access controls to limit exposure of systems running tcpdump to untrusted network traffic. The patch for this vulnerability specifically addresses the ubik_print() function by adding proper bounds checking and input validation to prevent over-read conditions when processing Rx protocol packets. Security teams should also monitor their network traffic analysis tools for any signs of exploitation attempts and maintain updated threat intelligence feeds to identify potential attack patterns targeting this specific vulnerability. Regular vulnerability assessments and penetration testing should include verification of tcpdump versions and configuration to ensure that systems remain protected against this and similar buffer over-read vulnerabilities.