CVE-2016-1417 in Snort
Summary
by MITRE
Untrusted search path vulnerability in Snort 2.9.7.0-WIN32 allows remote attackers to execute arbitrary code and conduct DLL hijacking attacks via a Trojan horse tcapi.dll that is located in the same folder on a remote file share as a pcap file that is being processed.
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Analysis
by VulDB Data Team • 05/14/2026
The vulnerability identified as CVE-2016-1417 represents a critical untrusted search path issue affecting Snort version 2.9.7.0-WIN32, specifically targeting Windows operating systems. This flaw resides in the software's handling of network packet capture files and demonstrates how improper path resolution can lead to severe remote code execution capabilities. The vulnerability exploits the software's tendency to search for dynamic link library dependencies in predictable locations, creating opportunities for malicious actors to place malicious files in directories where legitimate software expects to find supporting libraries.
The technical exploitation mechanism involves a Trojan horse approach where attackers place a malicious tcapi.dll file in the same directory as a pcap file that Snort processes. This specific DLL hijacking technique leverages the Windows dynamic link library loading mechanism, where the operating system searches for required libraries in a predetermined order including the current working directory. When Snort processes a pcap file from a remote file share, it inadvertently loads the malicious tcapi.dll from the same directory instead of the legitimate system library, effectively executing attacker-controlled code with the privileges of the Snort process. This vulnerability falls under the CWE-427 Uncontrolled Search Path Element category, which specifically addresses the dangerous practice of allowing applications to search in directories controlled by untrusted users.
The operational impact of this vulnerability extends beyond simple remote code execution, as it enables sophisticated attack chains that can lead to complete system compromise. Attackers can leverage this vulnerability to establish persistent backdoors, escalate privileges, or conduct lateral movement within network environments. The remote nature of the attack means that adversaries do not require local access to the system, making it particularly dangerous for network monitoring systems that process files from untrusted sources. This vulnerability directly aligns with ATT&CK technique T1059.001 for command and scripting interpreter, and T1068 for exploit for privilege escalation, as the initial code execution can be leveraged to gain higher system privileges.
Mitigation strategies for this vulnerability require immediate patching of Snort installations to versions that address the untrusted search path issue. Organizations should implement network segmentation to limit access to Snort processing directories and employ strict file access controls that prevent unauthorized DLL placement. System administrators should also consider implementing application whitelisting policies that restrict which DLLs can be loaded by Snort processes, and deploy monitoring solutions that detect suspicious DLL loading patterns. Additionally, network administrators should ensure that remote file shares containing pcap files are properly secured and that Snort is configured to process files from trusted, isolated environments. The vulnerability demonstrates the critical importance of proper library loading practices and highlights the need for security-conscious development practices that avoid predictable search paths in security-critical applications.