CVE-2017-11545 in tcpdump
Summary
by MITRE
tcpdump 4.9.0 has a Segmentation Violation in the compressed_sl_print function in print-sl.c:253:34.
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Analysis
by VulDB Data Team • 01/06/2021
The vulnerability identified as CVE-2017-11545 represents a critical segmentation fault within tcpdump version 4.9.0, specifically manifesting in the compressed_sl_print function located in the print-sl.c file at line 253 column 34. This issue arises from improper handling of compressed SLIP (Serial Line Internet Protocol) packet data during network traffic analysis operations, creating a potential crash condition that can be exploited by malicious actors to disrupt network monitoring services.
The technical flaw stems from inadequate input validation and memory access controls within the packet parsing routine. When tcpdump processes compressed SLIP frames, the compressed_sl_print function fails to properly validate the length or structure of incoming data before attempting to access memory locations. This oversight creates a classic buffer over-read condition where the application attempts to read beyond allocated memory boundaries, resulting in a segmentation violation that terminates the tcpdump process. The vulnerability is categorized under CWE-125 as an out-of-bounds read, which directly maps to the memory access violation pattern observed in this exploit scenario.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be leveraged in broader network security contexts. Network administrators relying on tcpdump for traffic monitoring and analysis face potential denial of service conditions when maliciously crafted packets trigger the segmentation fault. This vulnerability particularly affects environments where tcpdump is used in automated monitoring systems or security operations centers where continuous network visibility is critical. The crash condition can be triggered through network traffic injection attacks or by processing malformed compressed SLIP packets, making it a significant concern for network security infrastructure.
Mitigation strategies for CVE-2017-11545 should prioritize immediate patch application to tcpdump version 4.9.1 or later, which includes the necessary memory validation fixes. System administrators should implement network segmentation and access controls to limit exposure to potentially malicious traffic. Additionally, monitoring solutions should be configured to detect and alert on tcpdump process crashes or restarts, as these events may indicate exploitation attempts. The vulnerability demonstrates the importance of input validation in network security tools and aligns with ATT&CK technique T1499.001 for network disruption through service availability attacks, making it a critical concern for organizations maintaining network monitoring capabilities. Organizations should also consider implementing alternative packet analysis tools or implementing additional network security controls to prevent exploitation of similar vulnerabilities in other network monitoring applications.