CVE-2017-6430 in Ettercap
Summary
by MITRE
The compile_tree function in ef_compiler.c in the Etterfilter utility in Ettercap 0.8.2 and earlier allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted filter.
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Analysis
by VulDB Data Team • 12/28/2024
The vulnerability identified as CVE-2017-6430 resides within the Etterfilter utility component of Ettercap version 0.8.2 and earlier, representing a critical security flaw that enables remote attackers to execute denial of service attacks through out-of-bounds read conditions. This issue specifically affects the compile_tree function located in the ef_compiler.c source file, which serves as a core component responsible for processing filter rules within the Ettercap network analysis and interception framework. The vulnerability manifests when the utility processes malformed or crafted filter inputs that trigger memory access violations beyond the allocated buffer boundaries, potentially leading to application crashes or system instability.
The technical implementation of this vulnerability stems from insufficient input validation and boundary checking within the compile_tree function's processing logic. When Etterfilter encounters a specially crafted filter rule, the function fails to properly validate array indices or buffer limits during tree compilation operations, resulting in unauthorized memory access patterns that can cause the application to read data from memory locations outside the intended boundaries. This type of flaw falls under the CWE-129 vulnerability category, which specifically addresses insufficient validation of array indices, and represents a classic example of buffer over-read conditions that can be exploited to trigger denial of service scenarios. The attack vector is particularly concerning as it requires no authentication or privileged access, making it accessible to remote adversaries who can simply submit malicious filter rules to the affected system.
The operational impact of this vulnerability extends beyond simple service disruption, as it can potentially compromise the integrity of network monitoring operations that rely on Ettercap for packet analysis and filtering. When exploited, the out-of-bounds read condition can cause the Etterfilter utility to crash unexpectedly, forcing network administrators to restart services and potentially disrupting ongoing network analysis activities. In environments where Ettercap is deployed for security monitoring, intrusion detection, or network traffic inspection, such a vulnerability could be leveraged by attackers to create persistent denial of service conditions that degrade network security capabilities. The flaw's remote exploitability means that attackers can target systems without requiring physical access or local privileges, making it particularly dangerous in networked environments where Ettercap might be exposed to untrusted network traffic or user inputs.
Mitigation strategies for CVE-2017-6430 should prioritize immediate patching of affected Ettercap installations to version 0.8.3 or later, which contains the necessary code modifications to address the buffer validation issues in the compile_tree function. System administrators should implement input sanitization measures that validate all filter rule syntax before processing, including bounds checking for array indices and proper memory allocation verification. Network segmentation and access controls should be enhanced to limit exposure of Ettercap instances to untrusted networks or users who might submit malicious filter configurations. The vulnerability's classification under ATT&CK technique T1499.004 for network denial of service indicates that defensive measures should include monitoring for abnormal process termination patterns and implementing intrusion prevention systems that can detect and block malicious filter rule submissions. Additionally, organizations should conduct comprehensive vulnerability assessments to identify other potential instances of similar buffer over-read conditions within the Ettercap codebase and related network analysis tools.